Patent Application
20080245478
1. Field of Invention
The present invention pertains to a surface treatment apparatus using non-thermal equilibrium low temperature plasma. Invention particularly relates to a surface treatment apparatus that facilitates miscellaneous inner wall processing of treatment objects, which may include a long (several meters long) and narrow (several millimeters of inside diameter) dielectric tube.
2. Description of the Related Art
Liquid in a narrow tube contact with inner wall of the narrow tube at a specific contact angle, the value of the contact angle depends upon surface property of inner wall such as hydrophobic or hydrophilic behavior and geometry of inner wall such as glassy shape or hollow shape. An upward force in a pipe of a capillary action depends on the product of surface tension, cosine of a contact angle, and circumferential length of a hole. A downward force depends on the product of pressure, gravity, specific gravity of the liquid and height of the liquid. Therefore, the height of the liquid in a narrow tube can be calculated by equating the upward force and the downward force. For example, a column of water rises about 0.75 m in an atmospheric pressure in a pipe element having an inside diameter of 20 micrometers. However, in the inner wall of a narrow tube, it is difficult that liquid is transported at high speed. Therefore, as against inside of a long-narrow tube, it is extremely difficult to execute pasteurization, sterilization or washing by wet processing. Because of these problems, dry-process is suitable for inner wall processing of a long-narrow tube by non-thermal equilibrium low temperature plasma, which is full of radicals, is expected to process inner wall of a narrow tube.
Ichiki et al. have proposed an employment of plasma jet generated by inductively-coupled-high-frequency plasma for the dry-process of inner wall of a narrow tube is tried (See T. Ichiki et al., “Localized and ultrahigh-rate etching of silicon wafers using atmospheric-pressure microplasma jet”, J. Appl. Phys., 95 (2004) pp. 35-39). Plasma length of Ichiki et al is around several centimeters to the utmost.
Fujiyama proposed a configuration in which a metal electrode is interposed in a narrow tube so as to establish a pulsed discharge. However, it is extremely difficult to interpose the metal electrode in inside of a narrow tube having an inside diameter of less than several millimeters (See H. Fujiyama, “Inner coating of long-narrow tube by plasma sputtering”, Surface and Coating Technology, 131 (2000) pp. 278-283).
In particular, because medical instrument such as endoscope encompasses optical system and metallic parts having very minute geometry, the metallic part rises to a considerable high temperature, when the medical instrument are sterilized by plasma, even though low temperature plasma is employed. The rising to the high temperature generates a problem that warp or misalignment is produced in the optical system.
Because of these problems, under the present situations, in order to remove microbes adhered to an endoscope, a medical staff must dip the endoscope in antiseptic solution, and wash off microbes carefully from the endoscope with several stages in the antiseptic solution.
In view of these situations, Fukuda has proposed another sterilization method in a double tube structure, establishing washing in water and sterilization by plasma (See JP2006-21027 A). A long-narrow tube to be sterilized is dipped into water, which is filled in an inner tube made of glass, and the inner tube is installed in an outer tube. The plasma generated in a space between the inner tube and the outer tube is irradiated to long-narrow tube through the inner tube. However, in the double tube method proposed by Fukuda because a basis of sterilization is wet processing, there is a limit in the sterilization capability.
Therefore, no effective plasma generation method is proposed, which can be applied to in the inside of a long-narrow tube, having a length of several meters and an inside diameter of several millimeters, until now.
In particular, because dissociation energy of nitrogen molecules is so large compared with other gas molecules, as shown in table 1, as for the generation of nitrogen plasma, stable generation was very difficult until now.
In view of these situations, it is an object of the present invention to provide a surface treatment apparatus, which can treat surfaces of inner walls of various kinds of treatment objects, including a long-narrow tube having a length of several meters with an inside diameter of several millimeters. Hereinafter, the term “inner wall treatment” shall mean any surface treatment of a surface of inner wall of the subject treatment object. In addition, the term “surface treatment” shall mean any surface treatment of a surface of inner wall (inner surface) or the outer wall (outer surface) of the subject treatment object, which may include pasteurization, sterilization, and improvement of wettability. In a wide sense, the term “surface treatment” shall mean any removal of adhered materials, such as organic/inorganic materials, adhered to the surface of inner wall (inner surface) or the outer wall (outer surface) of the treatment object and any change of physical or chemical property of inner surface or the outer surface of the treatment object.
The term “change of physical or chemical property” shall include deposition or etching by plasma reaction. Therefore, a process to deposit a film made of material different from inner surface of the treatment object corresponds to the term “change of physical or chemical property”.
An aspect of the present invention inheres in a surface treatment apparatus encompassing a gas introducing system for introducing a process gas from an upstream end of a tubular treatment object; a vacuum evacuating system for evacuating the process gas from a downstream end of the treatment object;
an excited particle supplying system disposed at upstream side of the treatment object, for supplying excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby the inner surface of the treatment object is treated.
Another aspect of the present invention inheres in a surface treatment apparatus encompassing a vacuum evacuating system for evacuating a process gas introduced at a specific flow rate from a feed pipe provided at first end of a tubular treatment object having a blind wall at a second end, from an exhaust pipe provided at the first end, and maintaining the pressure of the process gas inside the treatment object at a process pressure; an excited particle supplying system disposed at upstream side of the treatment object, for supplying excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby the inner surface of the treatment object is treated.
Still another aspect of the present invention inheres in a surface treatment apparatus encompassing a vacuum manifold unit connected to a first end of a tubular treatment object having a blind wall at a second end, for confining hermetically process gas at specified pressure inside of the treatment object from the first end; an excited particle supplying system disposed at the first end side, for supplying excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby the inner surface of the treatment object is treated.
Further aspect of the present invention inheres in a surface treatment apparatus encompassing a vacuum evacuating system configured to evacuate process gas introduced from an upstream end of a tubular trunk pipe of a treatment object to generate a gas flow, the treatment object having the tubular trunk pipe and a branch pipe branched off from the trunk pipe, from a downstream end of the trunk pipe and an end portion of the branch pipe; an excited particle supplying system disposed at the upstream side of the treatment object, configured to supply excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 107 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby an inner surface of the treatment object is treated.
Still further aspect of the present invention inheres in a surface treatment apparatus encompassing a vacuum evacuating system configured to evacuate process gas introduced from a downstream end of a tubular trunk pipe of a treatment object and an end portion of a branch pipe of the treatment object to generate a gas flow, the treatment object having the tubular trunk pipe and the branch pipe branched off from the trunk pipe, from an upstream end of the trunk pipe; an excited particle supplying system disposed at the upstream side of the treatment object, configured to supply excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby an inner surface of the treatment object is treated.
Still further aspect of the present invention inheres in a surface treatment apparatus encompassing an excited particle supplying system disposed at upstream-side of a tubular treatment object made of dielectric material, the treatment object having a length greater than the diameter, for supplying excited particles for inducing initial discharge in a main body of the treatment object; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein a process gas is introduced from one end of the treatment object to form a gas flow inside of the treatment object, and the pressure of the gas flow is adjusted to a process pressure in a range of 20 kPa to 100 kPa, the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode to generate a non-thermal equilibrium plasma flow inside the treatment object, and thereby the inner surface of the treatment object is treated.
Still further aspect of the present invention inheres in a surface treatment apparatus encompassing a dielectric housing configured to accommodate an treatment object; a gas introducing system configured to introduce a process gas from an upstream end of the dielectric housing; a vacuum evacuating system configured to evacuate the process gas from a downstream end of the dielectric housing; an excited particle supplying system disposed at upstream side of the dielectric housing, configured to supply excited particles for inducing initial discharge in a main body of the dielectric housing; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the dielectric housing, and thereby a surface of the treatment object is treated.
Still further aspect of the present invention inheres in a surface treatment apparatus encompassing a dielectric housing configured to accommodate an treatment object; a vacuum evacuating system cored to evacuate a process gas introduced at a specific flow rate from a feed pipe provided at a first end of the dielectric housing having a blind wall at a second end, from an exhaust pipe provided at the first end, and maintaining the pressure of the process gas inside the dielectric housing at a process pressure; an excited particle supplying system disposed at first end of the dielectric housing, configured to supply excited particles for inducing initial discharge in a main body of the dielectric housing; and a first main electrode and a second main electrode disposed oppositely to each other, defining a treating region of the treatment object as a main plasma generating region disposed therebetween, wherein the excited particle supplying system is driven at least until generation of main plasma, and main pulse of duty ratio of 10−7 to 10−1 is applied across the first main electrode and second main electrode, to generate a non-thermal equilibrium plasma flow inside the dielectric housing, and thereby a surface of the treatment object is treated.
Other and further objects and features of the present invention will become obvious upon an understanding of the illustrative embodiments about to be described in connection with the accompanying drawings or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employing of the present invention in practice.
Various embodiments of the present invention will be described with reference to the accompanying drawings. It is to be noted that the same or similar reference numerals are applied to the same or similar parts and elements throughout the drawings, and the description of the same or similar parts and elements will be omitted or simplified. Generally and as it is conventional in the representation of semiconductor devices, it will be appreciated that the various drawings are not drawn to scale from one figure to another nor inside a given figure, and in particular that the layer thicknesses are arbitrarily drawn for facilitating the reading of the drawings.
In the following description specific details are set forth, such as specific materials, processes and equipment in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known manufacturing materials, processes and equipment are not set forth in detail in order not to unnecessarily obscure the present invention. Prepositions, such as “on”, “over”, “under”, “beneath”, and “normal” are defined with respect to a planar surface of the object component, regardless of the orientation in which the object component is actually held. A layer is on another layer even if there are intervening layers.
As shown in
In
The technical feature such that, in a surface treatment apparatus related to the first embodiment, a long-narrow tube having an inside diameter of less than or equal to 7-5 millimeters and a length of more than 4-7 meters is supposed to be employed as the treatment object 21 having tubular geometry, but even if the length is equal to or less than 4 meters long or inside diameter is more than 7 millimeters, the treatment object 21 can be processed, may be understood from the following discussion.
In particular, as for the technical advantage of the surface treatment apparatus related to the first embodiment, because, in Ichiki's methodology, the length of a microplasma is several centimeters at longest, a tube having a length of around 10 centimeters can achieve a significant effectiveness over Ichiki's methodology. In view of the technology taught by Ichiki's methodology, in a technical field of plasma, a tube having an inside diameter of equal to or less than 7-5 millimeters, a length of more than around 10 centimeters can be defined as “a long-narrow tube”. In addition, a cross-section of treatment object 21 is not limited to a circle, but polygons, including rectangle, can be employed. However, as for the long-narrow tubes adapted for industrial applications, there will be many cases that the long-narrow tubes have a circular cross-section. Although as representative long-narrow tube, medical instrument such as an endoscope (fiber scope) is well known, the technical concept of “a long-narrow tube” covers through various kinds of narrow tubes. For example, narrow tubes adapted for drinking water, which is used in vending machines can be included in the technical concept of “a long-narrow tube”.
When the treatment object 21 is a flexible long-narrow tube having an inside diameter equal to or less than around several millimeters, and a length of more than around several meters, and further the length is known beforehand, as shown in
Anyhow, the configuration with the treatment object guide grooves 22 shown in
If the treatment object 21 is the flexible long-narrow tube, rather than the configuration shown in
The excited particle supplying system (16, 17 and 18) encompasses a first auxiliary electrode 17, a second auxiliary electrode 18 facing to the first auxiliary electrode 17 so as to sandwich the upstream side of the treatment object 21, implementing a parallel plate configuration, and an auxiliary pulse power supply 16 configured to supply electric pulses between the first auxiliary electrode 17 and the second auxiliary electrode 18. The excited particle supplying system (16, 17 and 18) is provided so as to the starting voltage of the discharges and to generate initial plasma so as to facilitate generation of the plasma in the treatment object 21.
In addition to the effect such that generated plasma or excited particle are transported by diffusion and flow of process gas to arrive in the inside of the treatment object 21, an effect of irradiation by the light emitted from the generated plasma in the excited particle supplying system (16, 17 and 18) can be expected so that light can ionize neutral particles in the treatment object 21. Once plasma is generated in the treatment object 21, and if density of charged particles is large enough, an discharge is realized in the treatment object 21 only by the electric field established between the first main electrode Hand the second main electrode 12, and the generated plasma can be maintained in the treatment object 21. In this stage, the excited particle supplying system (16, 17 and 18) is not needed any more. Therefore, the excited particle supplying system (16, 17 and 18) is employed only at the initial stage of the plasma generation.
In addition, because it is enough that initial plasma can be injected in the gas flow in the early stage, the excited particle supplying system may be implemented by any other configuration such as an inductive plasma source which can generate initial plasma, and the excited particle supplying system is not limited to the parallel plate configuration shown in
After excitation of initial plasma, the surface treatment apparatus shown in
In the surface treatment apparatus related to the first embodiment, the process gas is supplied in the treatment object 21 as shown in
Intake adapter 24 shown in
A high voltage pulse having a duty ratio of 10−7 to 10−1 is applied across the first main electrode 11 and the second main electrode 12.
In the surface treatment apparatus related to the first embodiment of the present invention, duty ratio of 10−7 to 10−1 is preferable for the voltage pulse. If the duty ratio is less than 10−7, the discharge becomes unstable, and if the duty ratio is more than 10−1, unfavorable effect of heat plasma becomes prominent. The duty ratio of around 0.003-0.01 is more preferable. In addition, even a barrier discharge by a low frequency alternating electric field can be used to generate low temperature plasma in the treatment object 21, but a large input power cannot be expected by the barrier discharge.
Even for finely machined optical system or medical instrument such as an endoscope, which includes metallic components, because the duty ratio can be set to be around 10−7 to 10−1 according to the surface treatment apparatus related to the first embodiment, metallic components will not rise to a considerable high temperature, and the optical system can overcome the problem that warp or misalignment is generated by thermal effect of the plasma.
When a treatment object 21 made of dielectric material is inserted between the first main electrode 11 and the second main electrode 12, implementing a parallel plate configuration, and if dielectric constant ε2 of the dielectric material is larger than dielectric constant ε1 of gas (relative dielectric constant=1), the approximate electric field distribution can be represented as shown in
Because the dielectric breakdown field depends upon the size of space, or if the ambient pressure at inside and outside of the treatment object 21 is the same, the dielectric breakdown field becomes large in the inside of the treatment object 21. Therefore, it is necessary to reduce the dielectric breakdown field in the treatment object 21, by an appropriate method, to generate discharge in the inside of the treatment object 21. One method is to reduce gas pressure in the inside of the treatment object 21, for discharge in the right side region of Paschen's curve.
As shown in
In the surface treatment apparatus related to the second embodiment, the treatment object 21 has a tubular geometry made of dielectric material as shown in
Because a periodic array of T-shaped protrusions, rather than flat slab configuration, is employed for the first main electrode 11b, we will call the electrode configuration shown in
In addition, as the allocations of the exhaust pipe 63 to be connected to the process chamber (23, 53, 54, 62), any site of the process chamber, rather than the downstream side of the treatment object 21 shown in
The ambient gas adjustment mechanism (62, 65, 66b, 25b) is implemented by a plurality of taper-shaped gas supply holes 66b penetrating through the first electrode protection layer (first main electrode protection layer) 25b, as shown in
The process chamber (23, 53, 54, 62) embraces four planes assigned to a rectangular parallelepiped, embraces the second electrode-covering insulator (second main electrode-covering insulator) 23, a chamber bottom lid 53, a chamber top lid 54 and an injection-adjusting chamber 62, and two side plates at a rearward portion of the paper (not illustrated) and at the near side (not illustrated) of the paper of
Furthermore, as shown in
In the process chamber (23, 53, 54, 62), through the feed pipe 61, feed valve 41 and the injection-adjusting chamber 62, process gas is supplied from gas source 33, and the flow of the process gas is shaped into the configuration of a uniform shower by the ambient gas adjustment mechanism (62, 65, 66b, 25b). The process gas supplied to inside of the process chamber (23, 53, 54, 62) from the ambient gas adjustment mechanism (62, 65, 66b, 25b) is exhausted by the exhaust pipe 63 from the process chamber (23, 53, 54, 62).
Therefore, as shown in
In
Similar to the first embodiment, a narrow tube having an inside diameter of less than or equal to 7-5 milimeters and a length of more than 4-7 meters may be used as the tubular treatment object 21 in the surface treatment apparatus related to the second embodiment. However, if the length is equal to or less than 4 meters, and the inside diameter is more than 7 millimeters, the tube can be similarly processed. In addition, a cross-section of the treatment object 21 is not limited to a circular geometry, as already explained in the first embodiment.
Although the illustration is omitted, if the treatment object 21 is a flexible long-narrow tube, by providing first and second reels which roll up the treatment object 21, downstream end of the treatment object 21 may be rewound from the first reel so that upstream end of the treatment object 21 can be rolled up by the second reel, and a plurality of partial surface treatments at the outside of the treatment object 21 can be executed sequentially so as to achieve a full length treatment along the flexible long-narrow tube.
In the surface treatment apparatus related to the second embodiment, a high purity nitrogen gas could be supplied as the process gas through the ambient gas adjustment mechanism (62, 65, 66b, 25b) in a shape of a shower, however the “process gas” is not limited to nitrogen gas. For example, for pasteurize or sterilize the outer surface of the treatment object 21, nitrogen gas being mixed with various kinds of active gas, which may include halogen based compound gas, can be adopted.
High voltage pulses having duty ratio of 10−7 to 10−1 are applied across the first main electrode 11b and the second main electrode 12.
Because the period of the high voltage pulse is 500 microseconds, as shown in
To generate the discharge in the hermetically sealed space surrounding the outside of the treatment object 21, the feed valve 41 and the exhaust valve 42 are adjusted so that internal gas pressure P2 of the process chamber (23, 53, 54, 62) is equal to the atmospheric pressure P3=101 kPa, or around 80-90 kPa, which is slightly lower than the atmospheric pressure P3. Under the condition such that, in the process chamber (23, 53, 54, 62), through the feed pipe 61 and the feed valve 41, the process gas is supplied from the gas source 33, if high voltage pulses with high repetition rate as shown in
As shown in
An array of first main electrodes 11c implement a periodic ladder structure, which arranges a plurality of bar (linear) electrodes in parallel as shown in
The second main electrode 12 serves as the cathode, and the surface treatment apparatus related to the first modification of the second embodiment supplies the process gas as a shower from the first main electrode 11c serving as the anode, the structure of the ambient gas adjustment mechanism (62, 27, 66c) to exhaust the process gas from the exhaust pipe 63 is different from the process chamber (23, 53, 54, 62) shown in
The ambient gas adjustment mechanism (62, 27, 66c) embraces a process chamber side wall 27, to which a plurality of gas supply holes 66c are provided, and an injection-adjusting chamber 62, the process gas is injected from the injection-adjusting chamber 62 as shown in
The plurality of gas supply holes 66c are arranged in a two-dimensional matrix with a uniform pitch, the gas supply holes 66c penetrate through the process chamber side wall 27, as shown in
Furthermore, the surface treatment apparatus related to the first modification of the second embodiment embraces a gas source 33 such as a gas cylinder configured to store process gas, a feed pipe 61 connected to the gas source 33, a feed valve 41 connected to the feed pipe 61 as shown in
In the process chamber (23, 53, 54, 62), through the feed pipe 61 and the feed valve 41, process gas is supplied from the gas source 33, and the flow of the process gas is shaped into the configuration of uniform shower by the ambient gas adjustment mechanism (62, 27, 66c). The process gas supplied by the ambient gas adjustment mechanism (62, 27, 66c) is exhausted by the exhaust pipe 63 from the process chamber (23, 53, 54, 62). Then, as shown in
The vacuum pump 31, through the exhaust pipe 63 and the exhaust valve 42, is connected to the process chamber (23, 53, 54, 62). It is preferable for the exhaust valve 42 to use the variable conductance valve through which the exhaust conductance can be adjusted. To establish a hermetically sealed space, a top treatment object holder 52 configured to hold the upstream end of the tubular treatment object 21 is connected to the chamber top lid 54, and a bottom treatment object holder 51 configured to hold the downstream end of the treatment object 21 is connected to the chamber bottom lid 53. Depending on materials, geometry and size of the treatment object 21, by applying required changes and modifications appropriately, the structure of the top treatment object holder 52 and the bottom treatment object holder 51 can be designed and manufactured with well-known architecture pertaining to gas joints or vacuum components, easily.
In
Similar to the first embodiment, a narrow tube having an inside diameter of less than or equal to 7-5 millimeters and a length of more than 4-7 meters may be used as the tubular treatment object 21 in the surface treatment apparatus related to the first modification of the second embodiment. However, even if the length is less than 4 meters, and the inside diameter is more than 7 millimeters inside diameter, the treatment object 21 can be processed. In addition, a cross-section of the treatment object 21 is not limited to a circular geometry, as already explained in the first embodiment.
Although the illustration is omitted, if the treatment object 21 is a flexible long-narrow tube, by providing first and second reels which roll up the treatment object 21, the treatment object 21 may be rewound from the first reel so that the treatment object 21 can be rolled up by the second reel and a plurality of partial surface treatments at the outside of the treatment object 21 can be executed sequentially so as to achieve a full length treatment along the flexible long-narrow tube.
In the surface treatment apparatus related to the first modification of the second embodiment, a high purity nitrogen gas can be supplied as the process gas through the ambient gas adjustment mechanism (62, 27, 66c), however the “process gas” is not limited to nitrogen gas. For example, for pasteurization or sterilization, nitrogen gas being mixed with various kinds of active gas such as halogen based compound gas can be adopted.
High voltage pulses having duty ratio of 10−7 to 10−1 are applied to between the first main electrode 11c and the second main electrode 12.
Because the period of the high voltage pulse is 500 microseconds, as shown in
To generate discharge in the hermetically sealed space surrounding the outside of the treatment object 21, the feed valve 41 and the exhaust valve 42 are adjusted so that internal gas pressure P2 of the process chamber (23, 53, 54, 62) is equal to the atmospheric pressure P3=101 kPa, or around 80-90 kPa, which is slightly lower than the atmospheric pressure P3. Under the condition such that, in the process chamber (23, 53, 54, 62), through the feed pipe 61 and the feed valve 41, the process gas is supplied from the gas source 33, if high voltage pulses with high repetition rate as shown in
As shown in
The configuration of the first main electrode 11d such that a plurality of T-shaped protrusions, rather than flat slab configuration, are arranged as shown in
In the first modification shown in
Since other functions, configurations, and way of operation are substantially similar to the functions, configurations, and way of operation already explained in the second embodiment with
As shown in
In the first main electrode 11b, a plurality of T-shaped protrusions, rather than flat slab configuration, are arranged so as to implement the “quasi-parallel plate configuration” with the second main electrode 12 as shown in
The surface treatment apparatus related to the third embodiment encompasses the ambient gas adjustment mechanism (62, 65, 66b, 25b) configured to inject the process gas in a shape of a shower from the first main electrode 11b side, serving as the anode, to the second main electrode 12 side, serving as the cathode, and to exhaust the process gas through the second exhaust pipe 63 from the process chamber (23, 53, 54, 62), which is similar to the surface treatment apparatus related to the second embodiment, but is different from the surface treatment apparatus related to the first embodiment.
The cross-sectional view of the process chamber (23, 53, 54, 62) is illustrated such that, so as to implement four planes assigned to a rectangular parallelepiped, the process chamber (23, 53, 54, 62) embraces a second electrode-covering insulator (second main electrode-covering insulator) 23, a chamber bottom lid 53, a chamber top lid 54 and an injection-adjusting chamber 62. However, two side plates at a rearward portion of the paper and at the near side of the paper of
The injection-adjusting chamber 62 has a flat rectangular parallelepiped shape. Among the six planes assigned to each planes of a rectangular parallelepiped, five metallic planes implement the five planes of the rectangular parallelepiped, respectively, and the gas supply layer 65 implements one plane (which corresponds to the left side plane of the gas supply layer 65 in the cross-sectional view shown in
Furthermore, the gas introducing system (33, 67, 43, 60, 61, 41) of the surface treatment apparatus related to the third embodiment embraces a gas source 33 such as a gas cylinder configured to store process gas, a first feed pipe 67 connected to the gas source 33, a second feed pipe 61 connected to the gas source 33, a first feed valve 43 connected to second feed pipe 67, and a second feed valve 41 connected to the second feed pipe 61 as shown in
Through the first feed pipe 67 and the first feed valve 43, the process gas is supplied to the upstream side of the tubular dielectric treatment object 21 from the gas source 33, and because the process gas is evacuated by the vacuum pump (second pump) 31 provided at the downstream side of the tubular dielectric treatment object 21, the process gas flows in the tubular dielectric treatment object 21. Inner pressure of the tubular dielectric treatment object 21 is kept at a processing pressure of less than or equal to the atmospheric pressure, for example, around 20-30 kPa. On the other hand, in the process chamber (23, 53, 54, 62), through the second feed pipe 61 and the second feed valve 41, the process gas is supplied from the gas source 33, and the flow of the process gas is shaped into the configuration of uniform shower by the ambient gas adjustment mechanism (62, 65, 66b, 25b).
The process gas supplied by the ambient gas adjustment mechanism (62, 65, 66b, 25b) is exhausted through the second exhaust pipe 63 from the process chamber (23, 53, 54, 62). Then, as shown in
To establish the hermetically sealed space, a top treatment object holder 52 configured to hold the upstream end of the tubular dielectric treatment object 21 is connected to the chamber top lid 54, and a bottom treatment object holder 51, configured to hold the downstream end of the tubular dielectric treatment object 21, is connected to the chamber top lid 54. Depending on materials, geometry and size of the tubular dielectric treatment object 21, by applying required changes and modifications appropriately, the structure of the top treatment object holder 52 and the bottom treatment object holder 51 can be designed and manufactured with well-known architecture pertaining to gas joints or vacuum components, easily.
In
Similar to the first embodiment, a narrow tube having an inside diameter of less than or equal to 7-5 millimeters and a length of more than 4-7 meters may be used as the tubular dielectric treatment object 21 in the surface treatment apparatus related to the third embodiment as well, even if the length is equal to or less than 4 meters, and the inside diameter is more than 7 millimeters, the tubular dielectric treatment object 21 can be similarly processed. In addition, a cross-section of the tubular dielectric treatment object 21 is not limited to a circular geometry, as already explained in the first embodiment.
Although the illustration is omitted, if the tubular dielectric treatment object 21 is a flexible long-narrow tube, by providing first and second reels which roll up the tubular dielectric treatment object 21, the tubular dielectric treatment object 21 may be rewound from the first reel so that the tubular dielectric treatment object 21 can be rolled up by the second reel and a plurality of partial internal surface treatment of the tubular dielectric treatment object 21 may be executed sequentially.
In
In addition, similar to the case of the surface treatment apparatus related to the first embodiment, because it is enough that the initial plasma can be injected in the gas flow in the early stage, the excited particle supplying system may be implemented by any other configuration such as an inductive plasma source which can generate the initial plasma, therefore, the excited particle supplying system is not limited to the parallel plate configuration shown in
In the surface treatment apparatus related to the third embodiment, a high purity nitrogen gas can be supplied as the process gas in the tubular dielectric treatment object 21 from the upstream side, the “the process gas” is not limited to nitrogen gas. For example, for pasteurization or sterilization against inside and outside of the tubular dielectric treatment object 21, nitrogen gas being mixed with various kinds of active gas such as halogen based compound gas can be adopted.
High voltage pulses having duty ratio of 10−7 to 10−1 are applied across the first main electrode 11 and the second main electrode 12.
Because the period of the high voltage pulse is 500 microseconds, as shown in
In the surface treatment apparatus related to the third embodiment, there are three operation modes. That is to say, a first mode configured to ignite an discharge only in the inside of the tubular dielectric treatment object 21, a second mode configured to ignite an discharge only at the outside of the tubular dielectric treatment object 21, and a third mode configured to ignite discharges both inside and outside of the tubular dielectric treatment object 21 having tubular geometry.
As described in the surface treatment apparatus related to the first embodiment, when the tubular dielectric treatment object 21 made of dielectric material is inserted between the first main electrode 11b and the second main electrode 12 implementing a parallel plate configuration, if dielectric constant ε2 of the tubular dielectric treatment object 21 is larger than dielectric constant ε1 of gas, because the electric field distribution can be approximately illustrated as shown in
Therefore, in order to discharge selectively in the tubular dielectric treatment object 21, it is desirable that the internal gas pressure P1 in the tubular dielectric treatment object 21 is elected to be around 10−40 kPa, which is lower than the gas pressure P2 of the outside of the tubular dielectric treatment object 21.
And it is desirable that the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is elected to be equal to the atmospheric pressure P3=101 kPa, or to be around 80-90 kPa, which is slightly lower than the atmospheric pressure P3. Therefore, the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42 are adjusted such that the following relation can be satisfied:
P1<P2≦P3 (1).
Alternatively, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 is elected to be around 10−40 kPa, and the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is set to be less than or equal to 10−3 Pa to 10−5 Pa, by adjusting the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42 may be adjusted so that the following relation can be satisfied:
P2P1<P3 (2).
Because of these requirement for pressure control for example, a pressure gauge is provided to the first exhaust pipe 68 and the second exhaust pipe 63, so that the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42 can be adjusted by feed-back control. Or, mass-flow controllers configured to control the flow rate may be provided to the first feed pipe 67 and the second feed pipe 61. The first pressure gauge may be provided to each of the downstream side of the first feed valve 43 and the second feed valve 41. After setting the pressure condition as recited by Eq. (1) or (2), the second feed valve 41 and the second exhaust valve 42 are dosed so as to stop the gas-flow at outside of the tubular dielectric treatment object 21 so that the gas-flow is formed only in the inside of the tubular dielectric treatment object 21.
And, after the excited particle supplying system (17,18) is started so that initial plasma is supplied in the gas flow, if high voltage pulses having high repetition rate as shown in
In order to generate selectively plasma at the outside of the tubular dielectric treatment object 21, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 is elected to be a relatively higher pressure around 70-90 kPa, which is approximately equal to or a slightly higher than the pressure P2 at the outside of the tubular dielectric treatment object 21. And the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is set to be equal to the atmospheric pressure P3=101 kPa, or around 80-90 kPa, which is slightly lower than the atmospheric pressure P3. Then, the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42 are adjusted such that:
P1≦P2≦P3 (3).
But, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 is not necessary to be lower than the gas pressure P2 of the outside of the tubular dielectric treatment object 21. That is, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 can be set larger than the atmospheric pressure P3, or approximately equal to the atmospheric pressure P3=101 kPa, while the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is set to be approximately equal to the atmospheric pressure P3, or around 80-90 kPa, which is slightly lower than the atmospheric pressure P3 as:
P2≦P1≈P3 (4)
P2≦P3<P1 (5).
Alternatively, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 can be set to be less than or equal to 10−3 Pa to 10−5 Pa, while the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is set to be equal to the atmospheric pressure P3=101 kPa, or around 80-90 kPa, by adjusting the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42 so that the flowing condition can be satisfied:
P1P2≦P3 (6).
After controlling these pressures to the corresponding pressure conditions prescribed by Eqs. (3)-(6), the first feed valve 43 and the first exhaust valve 44 are dosed so as to stop the internal gas-flow in the inside of the tubular dielectric treatment object 21. And, in the process chamber (23, 53, 54, 62), via the second feed pipe 61 and the second feed valve 41, process gas is supplied from the gas source 33 in a shape of shower through the ambient gas adjustment mechanism (62, 65, 66b, 25b). Then, the high voltage pulses having high repetition rate as shown in
In order to generate the discharges in the inside and outside of the tubular dielectric treatment object 21, it is desirable that the gas pressure P1 in the inside of the tubular dielectric treatment object 21 is elected to be around 10−40 kPa, which is lower than the gas pressure P2 of the outside of the tubular dielectric treatment object 21. And the gas pressure P2 of the outside of the tubular dielectric treatment object 21 is set to be approximately equal to the atmospheric pressure P3=101 kPa, or set to be around 80-90 kPa, which is slightly lower than the atmospheric pressure P3 so that the pressure condition as shown by Eq. (1) can be satisfied, by adjusting the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42.
After controlling the pressure to the corresponding pressure condition as shown by Eq. (1), the excited particle supplying system (17,18) is started so that the initial plasma can be supplied in the gas flow. Simultaneously, in the process chamber (23, 53, 54, 62), the process gas is supplied in the shape of a shower by the ambient gas adjustment mechanism (62, 65, 66b, 25b). If the high voltage pulses having high repetition rate as shown in
A surface treatment apparatus related to a fourth embodiment of the present invention encompasses an accommodation tube 71 configured to accommodate a dielectric treatment object 21 of tubular geometry, or a long-narrow tube, as shown in
That is to say, the surface treatment apparatus related to the fourth embodiment embraces a gas cylinder configured to store process gas, a first feed valve 43 connected through the first feed pipe to the gas source 33, and a second feed valve 41 connected through the second feed pipe to the gas source 33.
Through the first feed pipe 67 and the first feed valve 43, the process gas is supplied to the upstream side of the tubular dielectric treatment object 21 from the gas source 33, and because the process gas is evacuated by the vacuum pump (first pump) 32 provided at the downstream side of the tubular dielectric treatment object 21, the process gas flows in the tubular dielectric treatment object 21. Inner pressure of the tubular dielectric treatment object 21 is kept at a processing pressure of less than or equal to the atmospheric pressure, for example, around 20-30 kPa.
On the other hand, in the process chamber (71, 72, 73) implemented by the accommodation tube 71, through the second feed pipe 61 and the second feed valve 41, the process gas is supplied from the gas source 33, and because the process gas is evacuated by the vacuum pump (second pump) 31 provided at the downstream side of the accommodation tube 71, the process gas flows in a space between the tubular dielectric treatment object 21 and the accommodation tube 71. Inner pressure of the accommodation tube 71 is kept at a processing pressure of less than and approximately equal to the atmospheric pressure, for example, around 80-90 kPa.
A top accommodating cap 73 and a bottom accommodating cap 72 are connected to the upper end and the bottom end of the accommodation tube 71, respectively, so that the space between the inner wall of the accommodation tube 71 and the outer wall of the tubular treatment object 21 can be vacuum evacuated, thereby a hermetically sealed space with double pipe structure is implemented.
Furthermore, the surface treatment apparatus related to the fourth embodiment embraces a first main electrode 11b, a second main electrode 12 facing to the first main electrode 11b so as to sandwich the treatment object 21, implementing a parallel plate configuration, a first auxiliary electrode 17 and a second auxiliary electrode 18 facing to the first auxiliary electrode 17 so as to sandwich the upstream side of the treatment object 21, implementing a parallel plate configuration.
It is desirable that, in order to generate discharges both in the inside of and at the outside of the tubular dielectric treatment object 21, the gas pressure P1 in the inside of the tubular dielectric treatment object 21 is elected to be around 10-40 kPa, which is slightly lower than the gas pressure P2 between the accommodation tube 71 and the tubular dielectric treatment object 21. And, it is desirable that the gas pressure P2 between the accommodation tube 71 and the tubular dielectric treatment object 21 is set to be equal to the atmospheric pressure P3=101 kPa, or around 80-90 kPa, which is slightly lower than the atmospheric pressure P3, by adjusting the first feed valve 43, the second feed valve 41, the first exhaust valve 44 and the second exhaust valve 42.
After controlling these pressures to the predetermined pressure conditions, the excited particle supplying system (17,18) is started so as to supply provide initial plasmas to the gas flow in the hermetically sealed space between the outside of the tubular dielectric treatment object 21 and accommodation tube 71 and to the gas flow in the inside of the tubular dielectric treatment object 21, thereafter, if high voltage pulses having high repetition rate as shown in
As shown in
A pot or bottle made of dielectric material can serve as the treatment object 20, and a neck adapter 19 is inserted in the neck of the pot-shaped treatment object 20, the neck is allocated at the first end of the pot-shaped treatment object 20. A excitation feed pipe 60 and an exhaust pipe 68 penetrate through the neck adapter 19 in parallel. The excitation feed pipe 60 is a hollow cylinder or a narrow tube made of dielectric material.
The process gas is introduced in the inside of the pot-shaped treatment object 20 by the excitation feed pipe 60 so that the process gas can be exhausted from the exhaust pipe 68. The first main electrode 11 and the second main electrode 12, implement a parallel plate configuration, by facing each other so as to sandwich the pot-shaped treatment object 20.
In one part of the excitation feed pipe 60, an excited particle supplying system (16, 17, 18) configured to supply initial plasma in the gas flow for stating the discharge is provided. The excited particle supplying system (16, 17, 18) is driven at least until generation of main plasma. The excited particle supplying system (16, 17, 18) embraces a first auxiliary electrode 17, a second auxiliary electrode 18, an auxiliary pulse power supply 16 configured to apply an electric pulse (an auxiliary pulse) across the first auxiliary electrode 17 and the second auxiliary electrode 18 so as to generate an initial plasma. The first auxiliary electrode 17 and the second auxiliary electrode 18 implement a parallel plate configuration. On the other hand, the pulse power supply 14 supplies an electric pulse (main pulse) across the first main electrode 11 and the second main electrode 12 to maintain the plasma in the inside of the pot-shaped treatment object 20, which is initiated by the initial plasma.
High voltage pulses having duty ratio of 10−7 to 10−1 are applied.
In
Furthermore, in the surface treatment apparatus related to the fifth embodiment, a feed valve 43 is connected to the excitation feed pipe 60, a feed pipe 67 is connected to the feed valve 43, a gas source 33 such as a gas cylinder configured to store process gas is connected to the feed pipe 67. It is preferable to adopt needle valves facilitating the adjustment of the flow rate as the feed valve 43.
On the other hand, the process gas introduced by the excitation feed pipe 60 is exhausted vacuum pump 32. Therefore, an exhaust valve 44 is provided to the exhaust pipe 68, and the vacuum pump 32 is connected to the exhaust valve 44, so that the exhaust valve 44 can control the pressure to an appropriate processing pressure, when the gas flow is introduced in the pot-shaped treatment object 20. It is preferable for the exhaust valve 44 to use the variable conductance valve through which the exhaust conductance can be adjusted.
The process gas is supplied from the gas source 33 in the inside of the pot-shaped treatment object 20 through the excitation feed pipe 60, which is inserted in the neck of the pot-shaped treatment object 20, such that the pressure is controlled at around 20-30 kPa, which is near the atmospheric pressure, but less than the atmospheric pressure, exhausting the process gas from the pot-shaped treatment object 20, by the vacuum pump 32 through the exhaust pipe 68 that is inserted in the neck of the pot-shaped treatment object 20.
When, in the surface treatment apparatus related to the fifth embodiment, if a distance between the first main electrode 11 and the second main electrode 12, implementing a parallel plate configuration, is set to be 15 millimeters, the high voltage pulse having a repetition frequency of 2 kHz and a voltage value of around 24 kV is preferably applied across the first main electrode 11 and the second main electrode 12.
Because the period of the high voltage pulse is 500 microseconds, as shown in
In the surface treatment apparatus related to the fifth embodiment, a high purity nitrogen gas can be supplied as the process gas in the pot-shaped treatment object 20 from the neck, the “the process gas” is not limited to nitrogen gas. For example, for pasteurize or sterilize inside of the pot-shaped treatment object 20, nitrogen gas being mixed with various kinds of active gas, which may include halogen based compound gas, can be adopted. In addition, as already described in the first embodiment, a cross-section of the pot-shaped treatment object 20 cut along the horizontal plane in
In addition, as generic concept of “the pot-shaped treatment object” in the fifth embodiment, in addition to the pot or bottle like shape as shown in
In
Furthermore, the first auxiliary electrode 17 and the second auxiliary electrode 18 may be disposed at a position where the first auxiliary electrode 17 and the second auxiliary electrode 18 can sandwich the neck adapter 19 as shown in
In addition, similar to the case of the surface treatment apparatus related to the first and the third embodiments, because it is enough that the initial plasma can be injected in the gas flow in the early stage, the excited particle supplying system (16, 17, 18) may be implemented by any other configuration such as an inductive plasma source which can generate the initial plasma, therefore, the excited particle supplying system (16, 17, 18) is not limited to the parallel plate configuration shown in
As shown in
The vacuum manifold unit (43,44,45,60,64,69,70) embraces a the excitation feed pipe 60 connected to the first end of the treatment object 21; a manifold valve 45 connected to and the excitation feed pipe 60; a T-shaped pipe 64 connected to the manifold valve 45; a first feed valve 43 and first exhaust valve 44 connected to the T-shaped pipe 64; a feed pipe 70 connected to the first feed valve 43; and an exhaust pipe 69 connected to the first exhaust valve 44. The excitation feed pipe 60 is a hollow cylinder or a narrow tube made of dielectric material. A gas source 33 is connected to feed pipe 70, and a vacuum pump 30 is connected to the exhaust pipe 69. The gas source 33 is a gas cylinder storing process gas. The first feed valve 43 can adopt a needle valve, which facilitate adjustment of the flow rate of the process gas.
The process chamber (23, 53, 54, 62) is connected to a second feed valve 41, and the second feed valve 41 is connected to the feed pipe 70 so that the process gas can be supplied from the gas source 33 to in the inside of the process chamber (23, 53, 54, 62). The process chamber (23, 53, 54, 62) embraces four planes assigned to a rectangular parallelepiped, embraces a second electrode-covering insulator (second main electrode-covering insulator) 23, a process chamber bottom lid 53, a process chamber top lid 54 and an injection-adjusting chamber 62. Similar to the third embodiment, a side plate at a rearward portion of the paper (not illustrated) and another side plate at the near side (not illustrated) of the paper of
At first, in the state that the first feed valve 43 is closed, the manifold valve 45 and the first exhaust valve 44 are opened so that inside of the treatment object 21 can be vacuum evacuated to an ultimate pressure (or background pressure) of about 10−1 Pa to 10−6 Pa by the vacuum pump 30.
Then, the first exhaust valve 44 is dosed, after the internal pressure of the tubular treatment object 21 has arrived to the ultimate pressure, and the first feed valve 43 is opened so that, through the T-shaped pipe 64, the manifold valve 45 and the excitation feed pipe 60, the process gas can be supplied to the inside of the tubular treatment object 21 from the gas source 33 via the first end of the tubular treatment object 21. When the internal pressure of the treatment object 21 is set around 20-30 kPa, which is near to the atmospheric pressure but less than the atmospheric pressure, the manifold valve 45 is dosed so that the internal pressure in the inside of the treatment object 21 can be maintained at a hermetically confined state with the processing pressure.
On the other hand, through the feed pipe 70 and the second feed valve 41, the process gas is supplied to the process chamber (23, 53, 54, 62), the process gas is supplied at a constant flow rate through the ambient gas adjustment mechanism (62, 65, 66b, 25b) from the gas source 33.
Similar to the third embodiment, the ambient gas adjustment mechanism (62, 65, 66b, 25b) embraces an injection-adjusting chamber 62, a gas supply layer 65 made of porous ceramics facilitating a uniform distribution of the process gas from the injection-adjusting chamber 62, a gas supply layer 65 as shown in
The ambient gas adjustment mechanism (62, 65, 66b, 25b) is implemented by a plurality of taper-shaped gas supply holes 66b penetrating through the first electrode protection layer (first main electrode protection layer) 25b, similar to the topology shown in
Therefore, the process gas is formed into a configuration of uniform shower through the ambient gas adjustment mechanism (62, 65, 66b, 25b), and the process gas is supplied so as to surround the outside of the treatment object 21 in the process chamber (23, 53, 54, 62). The process gas supplied through the ambient gas adjustment mechanism (62, 65, 66b, 25b) is exhausted through the second exhaust pipe 63 from the process chamber (23, 53, 54, 62).
Furthermore, the surface treatment apparatus related to the sixth embodiment embraces the excited particle supplying system (16,17,18) disposed at the first end side, configured to supply excited particles for inducing initial discharge in a main body of the treatment object 21 in the early stage of discharge, in main body of the treatment object 21 the process gas is confined hermetically; and the first main electrode 11b and the second main electrode 12 disposed oppositely to each other so as to sandwich the treatment object 21, implementing a parallel plate configuration, in the configuration as a whole; and a pulse power supply 14 configured to apply electric pulses (main pulses) across the first main electrode 11b and the second main electrode 12 so as to maintain plasma state generated by the injection of the excited particles, and to cause a plasma state in the inside of the treatment object 21.
Because a periodic array of T-shaped protrusions, rather than flat slab configuration, is employed for the first main electrode 11b, the configuration as a whole is called as “quasi-parallel plate configuration” in view of the situation such that each of discharge points originates at each tips of the T-shaped protrusions, and all of the tips of the T-shaped protrusion are arranged on a single plane as if they implement a virtual flat slab. In this case the first main electrode 11b is equivalent to an array of bar-shaped linear) electrodes arranged in parallel so as to implement a ladder, and the ladder can implement an approximately “parallel plate configuration” with the second main electrode 12.
To the chamber top lid 54, a top treatment object holder 52 configured to hold the second end (the upper end in FIG. 15,) side of the tubular treatment object 21 is attached, and a bottom treatment object holder 51 configured to hold the first end (the bottom end in
In
In
After excitation of initial plasma by injection of excited particles, in the surface treatment apparatus shown in
Main pulse (high voltage pulse) of duty ratio of 10−7 to 10−1 is applied across the first main electrode 11b and second main electrode 12, to generate a non-thermal equilibrium plasma flow inside the treatment object 21, and thereby an inner surface of the treatment object 21 is treated. Preferably, a high voltage pulse having the high repetition rate, which have been explained in the first embodiment, is applied across the first main electrode 11 and the second main electrode 12 (See
In the surface treatment apparatus related to the sixth embodiment, there are three operation modes explained in the third embodiment. That is to say, a first mode configured to ignite selectively an discharge only in the inside of the treatment object 21, a second mode configured to ignite an discharge only at the outside of the treatment object 21, a third mode configured to ignite both in the inside of and at the outside of the treatment object 21, although the treatment object 21 has the tubular geometry and the sealed second end. Similar to the third embodiment, those modes can be controlled with the pressure conditions prescribed by Eqs. (1)-(6). Since ways of operations of the three operation modes are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
An endoscope may correspond to an example of the treatment object (21, 21b) having the tubular trunk pipe 21 and the branch pipe 21b branched off from the trunk pipe 21 (hereinafter called as “the T-branched treatment object (21, 21b)”). A plurality of T-shaped protrusions, rather than flat slab electrode, implements the “quasi-parallel plate configuration” with the second main electrode 12. Similar to the second, the third, the sixth embodiment, because each of discharges originates from each tips of the T-shaped protrusions arranged periodically in a plane, in view of the configuration as a whole, the structure can be approximated as “parallel plate configuration”.
The surface treatment apparatus related to the sixth embodiment further embraces a process chamber (23, 53, 54, 62) surrounding the outside of the tubular treatment object having the branch. In the process chamber (23, 53, 54, 62), to the surface of the second main electrode 12 serving as the cathode, the process gas is injected in a shower from the first main electrode 11b serving as the anode. Similar to the third embodiment, so as to supply process gas in the shape of a shower in the process chamber (23, 53, 54, 62), the surface treatment apparatus related to the sixth embodiment further embraces a ambient gas adjustment mechanism (62, 65, 66b, 25b) in the process chamber (23, 53, 54, 62), and the process gas is exhausted through a second exhaust pipe 63 from the process chamber (23, 53, 54, 62).
The process chamber (23, 53, 54, 62) embraces six planes assigned to each planes of a rectangular parallelepiped, such as a second electrode-covering insulator (second main electrode-covering insulator) 23, a chamber bottom lid 53, a chamber top lid 54 and an injection-adjusting chamber 62, and two side plates at a rearward portion of the paper (not illustrated) and at the near side (not illustrated) of the paper of
The injection-adjusting chamber 62 has a flat rectangular parallelepiped shape. Among the six planes assigned to each planes of a rectangular parallelepiped, five metallic planes implement the five planes of the rectangular parallelepiped, respectively, and the gas supply layer 65 implements one plane (which corresponds to the left side plane of the gas supply layer 65 in the cross-sectional view shown in
To establish a hermetically sealed space with the process chamber (23, 53, 54, 62), a top treatment object holder 52 configured to hold the upstream end of the trunk pipe 21 (21, 21b) is provided to the chamber top lid 54, and to the chamber bottom lid 53, a branch holder 82 configured to hold an end of the branch pipe 21b, which is branched off at the branching site 10 from the tubular trunk pipe 21, and a bottom treatment object holder 81 configured to hold the downstream end of the tubular trunk pipe 21 are provided as shown in
The vacuum evacuating system (68, 68b, 44, 32) encompasses a first exhaust pipe 68 connected to the bottom treatment object holder 81, a branched portion exhaust pipe 68b, which is branched off from the first exhaust pipe 68, connected to the branch holder 82, a first vacuum pump (first pump) 32 connected to the downstream side of the first exhaust pipe 68, and a first exhaust valve 44 connected between the first exhaust pipe 68 and first vacuum pump (first pump) 32. By such a constitution, the first vacuum pump (first pump) 32 can vacuum evacuate, through the exhaust pipe 68, the branched portion exhaust pipe 68b and the first exhaust valve 44, the inside of the T-branched treatment object (21, 21b).
As shown in
On the other hand, on the second electrode (second main electrode) 12, the second electrode-covering insulator (second main electrode-covering insulator) 23 made of high purity quartz is disposed. Furthermore, the surface treatment apparatus related to the seventh embodiment embraces a second feed valve 41 connected to the injection-adjusting chamber 62, a second feed pipe 61 connected to the second feed valve 41, an excitation feed pipe 60 connected to the top treatment object holder 52, a first feed valve 43 connected to the excitation feed pipe 60, a first feed pipe 67 connected between the first feed valve 43 and a gas source 33 such as a gas cylinder configured to store the process gas, and a second feed pipe 61 connected between the second feed valve 41 and the gas source 33 as shown in
Through the first feed pipe 67 and the first feed valve 43, the process gas is supplied from the gas source 33 in the inside of the T-branched treatment object (21, 21b). When the process gas is supplied to the upstream side of the T-branched treatment object (21, 21b), by the vacuum pump (second pump) 31 provided at the downstream side, the process gas flows in the inside of the T-branched treatment object (21, 21b), and the internal pressure of the T-branched treatment object (21, 21b) is kept at a processing pressure of around 20-30 kPa, which is near to and less than the atmospheric pressure.
On the other hand, in the process chamber (23, 53, 54, 62), through the second feed pipe 61 and the second feed valve 41, the process gas is supplied from the gas source 33, and the flow of the process gas is shaped into the configuration of uniform shower through the ambient gas adjustment mechanism (62, 65, 66b, 25b). The process gas supplied through the ambient gas adjustment mechanism (62, 65, 66b, 25b) is exhausted through the second exhaust pipe 63 from the process chamber (23, 53, 54, 62). And, as shown in
In
Similar to the first embodiment, a narrow tube (trunk pipe 21) having an inside diameter of less than or equal to 7-5 millimeters and a length is more than 4-7 meters, aside from the branch pipe 21b, may be used as the T-branched treatment object (21, 21b) in the surface treatment apparatus related to the seventh embodiment. However, even if the length of the trunk pipe 21 is less than 4 meters, and the inside diameter is more than 7 millimeters, the T-branched treatment object (21, 21b) can be processed. In addition, as already described in the first embodiment, for both the branch pipe and the trunk pipe, cross-sections of the T-branched treatment object (21, 21b) cut along the horizontal plane in
In
After excitation of initial plasma, the surface-treatment apparatus shown in
A high voltage pulse having the high repetition rate or duty ratio of 10−7 to 10−1, which have been explained in the first embodiment, is applied across the first main electrode 11 and the second main electrode 12 (See
Therefore, a stable non-thermal equilibrium low temperature plasma is generated the efficiently, without generating heat plasma ascribable to the high frequency discharge. In the surface treatment apparatus related to the seventh embodiment, there are three operation modes explained in the third embodiment. That is to say, a first mode configured to ignite selectively an discharge in the inside of the T-branched treatment object (21, 21b), a second mode configured to ignite selectively an discharge only at the outside of the T-branched treatment object (21, 21b), a third mode configured to ignite discharges both inside and outside of the T-branched treatment object (21, 21b). Therefore, similar to the third embodiment, those three modes can be controlled with appropriate pressure conditions prescribed by Eqs. (1)-(6).
Since ways of operations of the three operation modes are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
As described in the seventh embodiment, an endoscope may correspond to an example of the treatment object (21, 21b) having the tubular trunk pipe 21 and the branch pipe 21b branched off from the trunk pipe 21 (hereinafter called as “the T-branched treatment object (21, 21b)”), but the topology is reversed such that the upstream side and the downstream side of the T-branched treatment object (21, 21b) of the seventh embodiment is just reversed.
As to the first main electrode 11b, a plurality of T-shaped protrusions rather than flat slab electrode are arranged periodically in a plane so as to implement the “quasi-parallel plate electrode”. Similar to the second, third, sixth, and seventh embodiments, because, in the first main electrode 11b, a plurality of T-shaped protrusions are arranged periodically, each of the discharges originates from each tips of the T-shaped protrusions, in view of the configuration as a whole, the structure can be approximated as “parallel plate configuration” with the second main electrode 12.
As shown in
As ultraviolet rays irradiation mechanism 91, semiconductor light emitting devices such as semiconductor lasers or light emitting diodes made of wideband gap semiconductors, which may include, for example, GaN based compound semiconductors, ZnSe based compound semiconductors, ZnO based compound semiconductors, SiC based compound semiconductors, are desirable for miniaturization of excited particle supplying system (85, 91, 92, 93).
However, even another lasers such as solid-state lasers or gas lasers, which can emit ultraviolet rays are available. As gas lasers, which can emit ultraviolet rays, excimer laser is preferable. When a large-scale ultraviolet rays irradiation mechanism 91, such as gas lasers including excimer laser, is used, such large-scale ultraviolet rays irradiation mechanism 91 shall be disposed outside of the excited particle generation room 85, and to activate process gas by the ultraviolet rays emitted from the ultraviolet rays irradiation mechanism 91, window materials such as sapphire, which can transmit the ultraviolet rays, shall be provided to a wall of the excited particle generation chamber 85. In this way, the ultraviolet rays emitted from the external ultraviolet rays irradiation mechanism 91, disposed outside of excited particle generation chamber 85, can be introduced between the first reflecting mirror 92 and the second reflecting mirror 93 via the through-hole of the first reflecting mirror 92, so as to cause multi-reflection between the first reflecting mirror 92 and the second reflecting mirror 93, and the process gas can be activated.
In the surface treatment apparatus related to the eighth embodiment, to the surface of the second main electrode 12 serving as the cathode, the process gas is injected in a shower from the first main electrode 11b serving as the anode. Similar to the third, the sixth, the seventh embodiments, so as to supply process gas in the shape of a shower, the surface treatment apparatus related to the eighth embodiment further-embraces a ambient gas adjustment mechanism (62, 65, 66b, 25b), and the process gas is exhausted through the second exhaust pipe 63 from the process chamber (23, 53, 54, 62). The process chamber (23, 53, 54, 62) embraces six planes assigned to each planes of a rectangular parallelepiped, such as a second electrode-covering insulator (second main electrode-covering insulator) 23, a chamber bottom lid 53, the chamber top lid 54 and an injection-adjusting chamber 62, two side plates at a rearward portion of the paper (not illustrated) and at the near side (not illustrated) of the paper of
The injection-adjusting chamber 62 has a flat rectangular parallelepiped shape. Among the six planes assigned to each planes of a rectangular parallelepiped, five metallic planes implement the five planes of the rectangular parallelepiped, respectively, and the gas supply layer 65 implements one plane (which corresponds to the left side plane of the gas supply layer 65 in the cross-sectional view shown in
To establish a hermetically sealed state, as shown in
The first exhaust pipe 68 is connected to the bottom treatment object holder 51. And the first vacuum pump (first pump) 32 is connected to the downstream side of the first exhaust pipe 68 through the first exhaust valve 44. By such a constitution, the first vacuum pump (first pump) 32 can vacuum evacuate the inside of the T-branched treatment object (21, 21b) through the exhaust pipe 68 and the first exhaust valve 44.
As shown in
Furthermore, the surface treatment apparatus related to the eighth embodiment embraces an excitation feed pipe 60 connected to a ceiling wall of the excited particle generation chamber 85, a first feed valve 43 connected to the excitation feed pipe 60, a second feed valve 41 connected to the injection-adjusting chamber 62, a first feed pipe 67 connected between the first feed valve 43 and a gas source 33 such as a gas cylinder configured to store the process gas, and a second feed pipe 61 connected between the second feed valve 41 and the gas source 33, as shown in
In the inside of excited particle generation chamber 85, through the first feed pipe 67, the first feed valve 43 and the excitation feed pipe 60, the process gas is supplied from the gas source 33, and the process gas is supplied to the upstream side of the T-branched treatment object (21, 21b).
The process gas being supplied in the inside of excited particle generation chamber 85 further flows into the apertures of the top treatment object holder 83 and the branch holder 84, which are provided at the bottom of the excited particle generation chamber 85, and the process gas is further transported to the trunk pipe 21 and the branch pipe 21b of the T-branched treatment object (21, 21b).
Then, in the inside of excited particle generation chamber 85, excited particles are generated, and the excited particles are transported through the top treatment object holder 83 and the branch holder 84 provided at the bottom of the excited particle generation chamber 85, and the excited particles are injected into the trunk pipe 21 and the branch pipe 21b of the T-branched treatment object (21, 21b), while initial plasmas are generated in the inside of the trunk pipe 21 of the T-branched treatment object (21, 21b) and inside of the branch pipe 21b.
The process gas supplied in the trunk pipe 21 of the T-branched treatment object (21, 21b) and the branch pipe 21b are mixed at the branching site 9, and are further exhausted by the vacuum pump (second pump) 31 provided at the downstream side of the T-branched treatment object (21, 21b), and the internal pressure of the T-branched treatment object (21, 21b) is kept at a processing pressure of around 20-30 kPa, which is near to and less than the atmospheric pressure.
On the other hand, as shown in
In
Similar to the first embodiment, a narrow tube (trunk pipe 21) having an inside diameter of less than or equal to 7-5 millimeters and a length is more than 4-7 meters, aside from the branch pipe 21b, may be used as the T-branched treatment object (21, 21b) in the surface treatment apparatus related to the eighth embodiment. However, even if the length of the trunk pipe 21 is less than 4 meters, and the inside diameter is more than 7 millimeters, the T-branched treatment object (21, 21b) can be processed. In addition, as already described in the first embodiment, for both the branch pipe and the trunk pipe, cross-sections of the T-branched treatment object (21, 21b) cut along the horizontal plane in
After excitation of initial plasma, as shown in
A high voltage pulse having duty ratio of 10−7 to 10−1, which have been explained in the first embodiment is applied across the first main electrode 11 and the second main electrode 12 (See
In the surface treatment apparatus related to the eighth embodiment, there are three operation modes explained in the third embodiment. That is to say, a first mode configured to ignite selectively an discharge only in the inside of the T-branched treatment object (21, 21b), a second mode configured to ignite selectively an discharge only at the outside of the T-branched treatment object (21, 21b), a third mode configured to ignite both inside and outside of the T-branched treatment object (21, 21b) having tubular geometry with a branch. Similar to the third embodiment, those three modes can be controlled with pressure conditions prescribed by Eqs. (1)-(6). Since ways of operations of the three operation modes are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
In the third, sixth to eighth embodiments, examples to control three operation modes with pressure conditions prescribed by Eqs. (1)-(6) are explained. A first mode configured to ignite selectively an discharge only in the inside of the treatment object 21, a second mode configured to ignite selectively an discharge only at the outside of the treatment object 21, a third mode configured to ignite both inside and outside of the treatment object 21 are controlled by choosing a pressure conditions prescribed by Eqs. (1)-(6). That is to say, the control of three operation modes can be executed with another parameters aside from the pressure of the process gas. Temperature of the process gas is one example of other parameters for controlling the three operation modes, therefore, in a surface treatment apparatus related to the ninth embodiment of the present invention, such control of the temperature of the process gas will be explained.
As illustrated in
However, the surface treatment apparatus related to the ninth embodiment of the present invention is different from the surface treatment apparatus related to the third embodiment in that a heating feed pipe 86 is connected to the feed valve 43 and a pre-heater 87 is provided around the heating feed pipe 86 so as to pre-heat the process gas, as shown in
Through the first feed pipe 67 and the first feed valve 43, the process gas is supplied from the gas source 33 in the inside of the tubular treatment object 21, such that the process gas is fly supplied to the upstream side, by the vacuum pump (second pump) 31 provided at the downstream side, the process gas flows in the inside of the treatment object 21, while the inner pressure of the treatment object 21 is kept at a predetermined pressure. Among the three operation modes, when a first mode configured to ignite selectively an discharge only in the inside of the treatment object 21 is desired, by selectively energize the process gas flowing in the inside of the treatment object 21 through the pre-heater 87 so as to increase the temperature of the process gas flowing in the inside of the treatment object 21, such that the temperature of the process gas flowing in the inside of the treatment object 21 is approximately 30-50 degrees Celsius higher than the temperature of the process gas applied to the outside of the treatment object 21, which is fed through the ambient gas adjustment mechanism (62, 65, 66b, 25b), a selective discharge is easily established only in the inside of the treatment object 21. Of course, in order to generate discharge selectively, is desirable to decrease the gas pressure P1 in the inside of the treatment object 21 lower than the gas pressure P2 at the outside of the treatment object 21, such that the gas pressure P1 in the inside of the treatment object 21 is set to be around 10-40 kPa. In addition, it is desirable to decrease the gas pressure P2 at the outside of the treatment object 21 such that the gas pressure P2 at the outside of the treatment object 21 is approximately equal to the atmospheric pressure P3=101 kPa, or is around 80-90 kPa, which is slightly lower than the atmospheric pressure P3, as prescribed by Eq. (1). However, the first mode configured to ignite selectively an discharge only in the inside of the treatment object 21 is more stably and surely achieved when the temperature of the process gas flowing in the inside of the treatment object 21 is increased such that the temperature of the process gas flowing in the inside of the treatment object 21 is approximately 30-50 degrees Celsius higher than the temperature of the process gas applied to the outside of the treatment object 21.
In addition, when the gas pressure P2 at the outside of the treatment object 21 is near to gas pressure P1 in the inside of the treatment object 21, the first mode configured to ignite selectively an discharge only in the inside of the treatment object 21 can be established easily.
Since the structure and configuration of the process chamber (23, 53, 54, 62) and the ambient gas adjustment mechanism (62, 65, 66b, 25b) are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
In addition, although the illustration is omitted, if a buried heater is established in the inside of the ambient gas adjustment mechanism (62, 65, 66b, 25b) so that the temperature of the process gas flowing outside of the treatment object 21 can be increase than the temperature of the process gas flowing in the inside of the treatment object 21, the second mode configured to ignite selectively an discharge only at the outside of the treatment object 21 can be easily established.
In addition, if a Peltier cooling unit is provided in the inside of the ambient gas adjustment mechanism (62, 65, 66b, 25b) so that, by electronic cooling (Peltier effect), the temperature of the process gas applied to the outside of the treatment object 21 is decreased lower than the temperature of the process gas flowing in the inside of the treatment object 21, the first mode configured to ignite selectively an discharge only in the inside of the treatment object 21 can be established easily. Instead of the Peltier cooling unit, piping of refrigerant gas may be provided in the inside of the ambient gas adjustment mechanism (62, 65, 66b, 25b), so that the temperature of the process gas applied to the outside of the treatment object 21 is decreased lower than the temperature of the process gas flowing in the inside of the treatment object 21, the first mode configured to ignite selectively an discharge only in the inside of the treatment object 21 can be established easily.
Others are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
As explained in the ninth embodiment, the control of three operation modes can be achieved by control mechanism of a parameter aside from pressure of the process gas. Although one example of other parameters is the temperature of the process gas, which has been explained in the surface treatment apparatus related to the ninth embodiment of the present invention, another methodology to use trigger gas will be explained in a surface treatment apparatus related to the tenth embodiment of the present invention, in which, in the early stage of discharge, by introducing the trigger gas selectively where the selective discharge is desired, the selective discharge can be easily established so as to control three operation modes.
As illustrated in
However, the surface treatment apparatus related to the tenth embodiment of the present invention is different from the surface treatment apparatus related to the third embodiment in that the surface treatment apparatus related to the tenth embodiment encompasses a first T-shaped pipe 67t, configured to introduce a first trigger gas, is connected to first feed valve 43c and a second T-shaped pipe 61t, configured to introduce a second trigger gas, is connected to the second feed valve 41c. Furthermore, to the first branch of the first T-shaped pipe 67, through a trigger gas introduction valve 43b and a first trigger gas introduction pipe 67b, a first trigger gas source 88a is connected, and to the second branch of the second T-shaped pipe 61t, through a trigger gas introduction valve 41b and a second trigger gas introduction pipe 61b, a second trigger gas source 88b is connected.
In
Furthermore, to the downstream side of the first T-shaped pipe 67t, an excitation feed pipe 60 is connected through a first manifold valve 43a. The excitation feed pipe 60 is a pipe made of dielectric material. On the other hand, to the second downstream side of the second T-shaped pipe 61t, an ambient gas adjustment mechanism (62, 65, 66b, 25b) is connected through a second manifold valve 41a.
Through the first feed pipe 67c, the first feed valve 43c, the first T-shaped pipe 67t, the first manifold valve 43a and the excitation feed pipe 60, the process gas is supplied from the gas source 33 to the inside of the tubular treatment object 21, and the process gas supplied to the upstream side of the tubular treatment object 21, by the vacuum pump first pump) 32 provided at the downstream side of the tubular treatment object 21, the process gas is forced to flow in the inside of the treatment object 21, while the inner pressure of the treatment object 21 is kept at a predetermined pressure.
Then, at the beginning of the discharge, and in a short time, the first trigger gas introduction valve 43b is opened, when the first mode configured to generate selectively the discharge only in the inside of the treatment object 21 is desired among three operation modes, and the first trigger gas flows from the first trigger gas source 88a, through the first trigger gas introduction valve 43b, the T-shaped pipe 67t, the first manifold valve 43a and the excitation feed pipe 60, to the inside of the treatment object 21 so that a selective discharge is easy established only in the inside of the treatment object 21.
Of course, the gas pressure P1 in the inside of the treatment object 21 is preferably decreased to be around 10-40 kPa in the inside of the treatment object 21 in order to generate discharge selectively, and it is desirable to decrease the gas pressure P1 lower than the gas pressure P2 at the outside of the treatment object 21. In addition, the gas pressure P2 at the outside of the treatment object 21 is elected to be equal to the atmospheric pressure P3=101 kPa, around 80-90 kPa which is slightly lower than the atmospheric pressure P3 as taught by Eq. (1). However, if the first trigger gas is selectively injected in the inside of the treatment object 21, like a pulse in a shot time, the first mode configured to selectively generate the discharge only in the inside of the treatment object 21 is stably and surely established. In addition, even in a case when the gas pressure P2 at the outside of the treatment object 21 is near to gas pressure P1 in the inside of the treatment object 21, the first mode configured to ignite selectively discharge only in the inside of the treatment object 21 is easily achieved by the introducing of the first trigger gas.
On the other hand, through the second feed pipe 61c, the second feed valve 41c, the second T-shaped pipe 61t, the second manifold valve 41a, the process gas is supplied from the gas source 33 to the ambient gas adjustment mechanism (62, 65, 66b, 25b), and the process gas supplied to the upstream side, by the vacuum pump (second pump) 31 provided at the downstream side of the process chamber (23, 53, 54, 62), the process gas is forced to flow in the process chamber (23, 53, 54, 62), while the process chamber (23, 53, 54, 62) is kept at a predetermined pressure.
Then, at the beginning of the discharge, and in a short time, the second trigger gas introduction valve 41b is opened, when the second mode configured to selectively generate discharge only at the outside of the treatment object 21 is desired, among three operation modes, the second trigger gas flows from the second trigger gas source 88b, through the second trigger gas introduction valve 41b, the T-shaped pipe 61t and the second manifold valve 41a, to the inside of the process chamber (23, 53, 54, 62) so that a selective discharge is easy established only at the outside of the treatment object 21.
Of course, in order to generate the discharge only at the outside of the treatment object 21, it is preferable to consider the pressure conditions prescribed by Eqs. (3), (4), (5) or (6), however by injecting pulse-like the second trigger gas, selective ignition of the discharge can be established more surely and more stably only at the outside of the treatment object 21. In addition, even in a case when the gas pressure P2 at the outside of the treatment object 21 is near to the gas pressure P1 in the inside of the treatment object 21, the second mode configured to ignite selectively discharge only at the outside of the treatment object 21 can be achieved surely and stably.
As to the third mode configured to generate discharges both in the inside and at the outside of the treatment object 21, both of the first and second trigger gases can be injected; only the first trigger gas is injected in the pressure condition such that only the discharge in the inside of the treatment object 21 is not easy; alternatively, only the second trigger gas is injected in the pressure condition such that only the discharge at the outside of the treatment object 21 is not easy; while the third mode can be established without employing the first and second trigger gases.
Since other structures or configurations, such as the configuration of the process chamber (23, 53, 54, 62) and the ambient gas adjustment mechanism (62, 65, 66b, 25b) are substantially similar to those already explained in the third embodiment, overlapping or redundant description might be omitted.
As shown in
The dielectric housing (74, 75 and 76) is implemented by a dielectric tube 74 and a dielectric flange plate 75. The dielectric tube 74 and the dielectric flange plate 75 is sealed by o-ring 76 so as to establish a vacuum tight structure. On the second main electrode 12, a second main electrode covering insulating film 77 is disposed so as to cover the surface of the second main electrode 12, and the dielectric housing (74, 75 and 76) is mounted and fixed on the second main electrode covering insulating film 77.
In
Furthermore, the first auxiliary electrode 17 and the second auxiliary electrode 18 may be disposed at a position sandwiching the neck adapter 19 as shown in
Although, in
As shown in
Although, in
As shown in
As shown in
As shown in
The flexible container 3b is a housing made of thin dielectric thin film. One plane of the flexible container 3b is made open such that ambient gas and plasma species can communicate between inside and outside of the flexible container 3b.
A pulse power supply 14 applies electric pulses (main pulses) across the array of first main electrodes 11a, 11b, 11c, 11d and 11e and the second main electrode 12, which implement a quasi-parallel plate configuration, so that the electric pulse can cause the fine-streamer discharge in the hermetically sealed space, which surrounds the outside of the flexible container 3b. In the ambient gas adjustment mechanism 79 a plurality of gas supply holes are provided in a form of two-dimensional matrix with a predetermined pitch. The main pulse of duty ratio of 10−7 to 10−1 is applied between the array of first main electrodes 11a, 11b, 11c, 11d and 11e and second main electrode 12, and the surface of the treatment object 5 is treated in non-thermal equilibrium plasma in the flexible container 3b.
If we assume the distance between the tip of the array of first main electrodes 11a, 11b, 11c, 11d and 11e and the top of the flexible container 3b is d, the film thickness of the flexible container 3b is t, and the inner height of the flexible container 3b is g, with ε1 for the dielectric constant of the process gas, and ε2 for the dielectric constant of flexible container 3b, the total capacitance Ctotal of the parallel plate capacitance with area S, which is defined against the plasma space is given by:
C
total
=S/(d/ε0ε1+2t/ε0ε2+g/ε0ε1) (7).
From Eq. (7), we understand that we can make electric field in the inside of the flexible container 3b larger than at the outside of the flexible container 3b, so that we can generate plasma only in the inside of the flexible container 3b. Namely, as shown in
As shown in
As shown in
Although
Various modifications will become possible for those skilled in the art after receiving the teaching of the present disclosure without departing from the scope thereof.
For example, each technical idea explained in first to thirteenth embodiments can be combined. For example, structure of the first main electrode 11c and the structure of the ambient gas adjustment mechanism (62, 27, 66c), with which the first modification of the second embodiment is explained, may be applied to the third, sixth to tenth embodiments. And, the structure of the first main electrode 11d and the third structure of the ambient gas adjustment mechanism (62, 25d, 66d), with which the second modification of the second embodiment is explained, may be applied to the third, sixth to tenth embodiments.
In addition, as the excited particle supplying system, the excitations by plasma discharges through parallel plate configurations are disclosed in the first to seventh and the ninth to thirteenth embodiments, and the excitation by ultraviolet rays is disclosed in the eighth embodiment, they are mere illustrations, and there are many other excitation mechanisms of various kinds for generating initial plasma. For example, as shown in
Alternatively, as shown in
In
Through a first outer wiring 67, the electric current introduction terminal (feedthrough) 7 is connected to the auxiliary pulse power supply 16, and the electric current introduction terminal (feedthrough) 7 is connected to the inner cylindrical shell (the second auxiliary electrode) 18a through an inner wiring 6c. In addition, the auxiliary pulse power supply 16 is connected to the outer cylindrical shell (the first auxiliary electrode) 17a through a second outer wiring 6a.
In addition, although the excitation of the process gas by ultraviolet rays using multi-reflection was explained in the eighth embodiment, it is not necessary to use the multi-reflection, and other methodologies such as the collinear introduction of the ultraviolet ray beam along the introduction direction of the process gas can generate the excited particles. In addition, the excited particles can be generated by irradiation of radioactive rays, aside from ultraviolet rays, such as synchrotron radiation, for example.
Furthermore, although the cases that a single treatment object is processed are illustrated in the first to thirteenth embodiments, a plurality of treatment objects can be processed simultaneously, if the first main electrode 11b and the second main electrode 12 are disposed so as to sandwich the plurality of treatment objects. If each of the inside of the plurality of treatment object is processed, a plurality of feed pipes and a plurality of exhaust pipe and accompanying valves shall be required for each treatment objects, respectively, of course.
Thus, the present invention of course includes various embodiments and modifications and the like, which are not detailed above. Therefore, the scope of the present invention will be defined in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-031297 | Feb 2007 | JP | national |
| 2007-068908 | Mar 2007 | JP | national |
This application is a continuation in part of U.S. patent application Ser. No. 11/826,957, filed on Jul. 19, 2007, abandoned, which claims benefit of priority under 35 USC 119 based on Japanese Patent Application No. P2007-31297 filed Feb. 9, 2007, and Japanese Patent Application No. P2007-68908 filed Mar. 16, 2007, the entire contents of which are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11826957 | Jul 2007 | US |
| Child | 12081913 | US |
