Patent Application
20140193573
The present invention relates to an apparatus used to form an electroconductive substance in micro holes provided in a substrate using a fluid including a metal complex dissolved in a supercritical fluid or a subcritical fluid and a method of forming the same.
In recent years, there has been a necessity for technologies to synthesize a target substance without using substances with a large environmental load such as organic solvents. Hitherto, for ultrafine fabrication processes such as the manufacturing of integration circuits, a dry process (vacuum process) in a vacuum, a dilute gas atmosphere, a plasma discharge atmosphere or the like has been frequently used.
The dry process has thus far been developed as an extremely effective means since a single atom or molecule or ions thereof can be directly used in the process. However, a facility used to maintain a vacuum environment or a plasma generation apparatus is required with the previously developed dry process, and they increase the cost. On the other hand, in wet processes in which a liquid is used, such as plating or cleaning, a large amount of liquid waste is generated. Therefore, there are problems of the large cost of treating the liquid waste and the high impact thereof on the environment.
Supercritical fluids of which CO2 is used as a medium have properties intermediate between liquid and solid, are in a state of zero surface tension, and also have unique properties such as a good solvent capability. Furthermore, supercritical fluids have advantages of being chemically stable, cheap, harmless and low cost. Additionally, CO2 and substances being dissolved in a CO2 fluid can be recycled through gasification and re-liquefaction.
Considerable attention has been paid to use the supercritical CO2 mainly for the wafer cleaning step in a semiconductor processing. For example, for the cleaning step, processes have been developed utilizing the properties such as solvent capability, stability and recyclability of supercritical CO2. In addition, nano-ordered fine wiring process have been also developed utilizing the property of zero surface tension in supercritical CO2 (for example, PCT International Publication No. WO 2005/118910).
Due to the zero surface tension and a large diffusion coefficient, supercritical fluids can deeply enter micro holes even when the size of the micro hole is in a nanoscale. When a supercritical fluid is available for use as a reaction field used to form thin films, it is possible to form and fill in ultrafine structures with substances, and furthermore, a low-cost clean process can be established instead of CVD or plating.
In recent years, with the growth of smaller and more functional electronic devices, there has been an increasing demand for a high-density packaging of LSI. However it is said that the current two-dimensional packaging techniques have come close to the limit. As a result, three-dimensional packaging technologies used to stack LSI chips have become necessary, and through-hole electrodes that are wired in a vertical direction (stacking direction) through a semiconductor substrate have been practically applied.
Through-hole electrodes are used not only for the three-dimensional stacking of the LSI chips but also for wiring substrates (interposers) used to mount the LSI at a high density. There are two typical types for through-hole electrodes, that is, a through-hole electrode including an electroconductive substance completely filled in micro holes and a through-hole electrode including an electroconductive substance deposited in a thin film shape on the inner walls of micro holes. Due to an increasing number of pins in wires in accordance with the advanced performance of LSI or the increased density and closer integration of packages, there is a demand for an additional decrease of through wires in size and pitch; and therefore, there is an issue in how to fill an electroconductive substance completely in micro holes with a high aspect ratio or in how to deposit an electroconductive substance at a uniform thickness.
The invention has been made in consideration of the above-mentioned conventional circumstances, and a first object of the invention is to provide an apparatus used to form an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
In addition, a second object of the invention is to provide a method of forming an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
An apparatus of a first aspect of the invention which forms an electroconductive substance, includes: a reaction chamber including a first space into which a fluid is introduced and a second space through which the fluid is discharged, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid; and a support member which supports a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber, and includes a first surface, a second surface, and micro holes, the support member supporting the substrate throughout an entire first surface so that the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and so that the fluid travels in the micro holes of the substrate from the second surface toward the first surface of the substrate, and includes fine communication holes through which the fluid passes toward the second space.
It is preferable that the apparatus of the first aspect of the invention which forms an electroconductive substance include an introduction portion which projects in the first space of the reaction chamber, includes an introduction opening configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
The apparatus of the first aspect of the invention which forms an electroconductive substance includes an introduction portion which projects in the first space of the reaction chamber, includes a plurality of introduction openings configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
A method of a second aspect of the invention which forms an electroconductive substance, includes: preparing: a reaction chamber including a first space into which a fluid is introduced and a second space through which the fluid is discharged, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid; a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber, and includes a first surface, a second surface, and micro holes; and a support member which supports the first surface of the substrate; disposing the support member so that the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and so that the fluid travels in the micro holes of the substrate from the second surface toward the first surface of the substrate; and allowing the fluid to transfer from the first space to the second space; and forming an electroconductive substance on inner walls of the micro holes provided in the substrate.
In the method of the second aspect of the invention which forms an electroconductive substance, it is preferable that a semiconductor substrate or a glass substrate be used as the substrate.
In the method of the second aspect of the invention which forms an electroconductive substance, it is preferable that the fluid contain a reducing agent dissolved therein.
An apparatus of a third aspect of the invention which forms an electroconductive substance, includes: a reaction chamber into which a fluid is introduced, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid, wherein a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber, and includes micro holes, and the substrate is disposed so that the fluid moves along both surfaces of the substrate.
In the apparatus of the third aspect of the invention which forms an electroconductive substance, it is preferable that the substrate be disposed so that both surfaces of the substrate are parallel to the specific direction.
In the apparatus of the third aspect of the invention which forms an electroconductive substance, it is preferable that the substrate be disposed so that both surfaces of the substrate are not parallel to the specific direction.
It is preferable that the apparatus of the third aspect of the invention which forms an electroconductive substance include a holding portion which holds an angle formed by both surfaces of the substrate with respect to the specific direction, and is provided in the reaction chamber.
A method of a fourth aspect of the invention which forms an electroconductive substance, includes: preparing: a reaction chamber into which a fluid is introduced; and a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber are prepared, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid; and allowing the fluid to transfer along both surfaces of the substrate; and forming an electroconductive substance on inner walls of the micro holes provided in the substrate.
In the method of the fourth aspect of the invention which forms an electroconductive substance, it is preferable that a semiconductor substrate or a glass substrate be used as the substrate.
In the method of the fourth aspect of the invention which forms an electroconductive substance, it is preferable that the fluid contain a reducing agent dissolved therein.
An apparatus of a fifth aspect of the invention which forms an electroconductive substance, includes: a reaction chamber including a first space into which a fluid is introduced and a second space through which the fluid is discharged, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid; and a support member which supports a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber, and includes a first surface, a second surface, and micro holes, the support member supporting the first surface of the substrate so that the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and so that the fluid travels in the micro holes of the substrate from the second surface toward the first surface of the substrate.
It is preferable that the apparatus of the fifth aspect of the invention which forms an electroconductive substance include an introduction portion which projects in the first space of the reaction chamber, includes an introduction opening configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
It is preferable that the apparatus of the fifth aspect of the invention which forms an electroconductive substance include an introduction portion which projects in the first space of the reaction chamber, includes a plurality of introduction openings configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
An apparatus of a sixth aspect of the invention which forms an electroconductive substance, includes: a reaction chamber including a first space into which a fluid is introduced and a second space through which the fluid is discharged, the fluid including at least a metal complex dissolved in a supercritical fluid or a subcritical fluid; and a support member which supports a planar substrate which is disposed in the fluid that continuously moves in a specific direction in the reaction chamber, and includes a first surface, a second surface, and micro holes, the support member supporting the first surface of the substrate so that the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and so that the fluid travels in the micro holes of the substrate from the second surface toward the first surface of the substrate, and includes a guide path through which the fluid passes toward the second space and which is provided around the substrate.
It is preferable that the apparatus of the sixth aspect of the invention which forms an electroconductive substance include an introduction portion which projects in the first space of the reaction chamber, includes an introduction opening configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
It is preferable that the apparatus of the sixth aspect of the invention which forms an electroconductive substance include an introduction portion which projects in the first space of the reaction chamber, includes a plurality of introduction openings configured to be located close to the second surface of the substrate, and introduces the fluid into the reaction chamber.
In the apparatus used to form an electroconductive substance according to the first aspect of the invention, it is possible to forcibly transport a fluid into the micro holes from both the first surface and the second surface of the substrate. Therefore, according to the invention, it is possible to provide an apparatus used to form an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
Particularly, in the apparatus used to form an electroconductive substance according to the first aspect of the invention, since the supporting portion which supports the substrate throughout the entire first surface and includes a fine communication hole through which the fluid passes toward the second space is disposed, the pressure difference between the top and bottom surfaces of the substrate increases, and it is possible to more reliably deposit an electroconductive substance in the micro holes. In addition, it is possible to reduce a load applied to the substrate. Then, it is possible to prevent the damage of the substrate and to prevent the clogging of the pipe and the malfunctioning of the device. As a result, according to the formation apparatus of the invention, a stable operation state is possible, a load applied to the substrate can be reduced, and it is possible to further extend the distance in which an electroconductive substance can be evenly deposited at a uniform thickness in the longitudinal direction of the micro holes provided in the substrate even in a case in which the length of the micro holes provided in the substrate increases due to an increase in the pressure difference.
Configuration examples of the fluid introduction portion include a case in which a pipe-shaped introduction portion is connected to the reaction chamber so as to be communicated with the first space α of the reaction chamber, a case in which the introduction portion projects in the first space α in the reaction chamber and an introduction opening is configured to be located close to the second surface of the substrate, and a case in which the introduction portion projects in the first space in the reaction chamber and a plurality of introduction openings are configured to be located close to the second surface of the substrate.
In the method of the second aspect of the invention which forms an electroconductive substance, it is possible to forcibly transport a fluid into the micro holes from both the first surface and the second surface of the substrate. Therefore, according to the invention, it is possible to provide a method of forming an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
Particularly, In the method of the second aspect of the invention which forms an electroconductive substance, since the supporting portion which supports the substrate throughout the entire first surface and includes the fine communication hole through which the fluid passes toward the second space is disposed, the pressure difference between the top and bottom surfaces of the substrate becomes large, and it is possible to more reliably deposit an electroconductive substance in the micro holes. In addition, it is possible to reduce the load applied to the substrate. Then, it is possible to prevent the damage of the substrate and to prevent the clogging of the pipe and the malfunctioning of the device. As a result, according to the forming method of the invention, a stable operation state is possible for a long period of time, the load applied to the substrate can be reduced, and a contribution is made to further extend the distance in which an electroconductive substance can be evenly deposited at an uniform thickness in the longitudinal direction of the micro holes provided in the substrate even in a case in which the length of the micro holes provided in the substrate increases due to an increase in the pressure difference.
In the method of the second aspect of the invention which forms an electroconductive substance, a semiconductor substrate or a glass substrate is preferable as the substrate. When the invention is made applicable to semiconductor substrates or glass substrates, the application to the three-dimensional packaging, interposers and the like of the above-described LSI can be expected. In addition, a fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. When the fluid contains a reducing agent dissolved therein, it is possible to supply a raw material and the reducing agent to the micro holes at the same time, and it is possible to form a uniform thin film.
In the apparatus used to form an electroconductive substance according to the third aspect of the invention, the fluid is transported to the micro holes through both “flowing” and “diffusion”. Therefore, it is considered that the fluid is well transported to the micro holes compared with a case in which only one surface of the substrate is exposed to the fluid flowing toward the substrate. Therefore, according to the invention, it is possible to provide an apparatus used to form an electroconductive substance which can deposit an electroconductive substance on the substrate at a uniform thickness.
Configuration examples of the substrate being disposed so that the fluid moves along both surfaces of the substrate include a case in which the substrate is disposed so that both surfaces of the substrate are parallel to the specific direction and a case in which both surfaces of the substrate are not parallel to the specific direction. In order to dispose the substrate as described above, the holding portion that holds an angle formed by both surfaces of the substrate with respect to the specific direction is preferably provided in the reaction chamber. In a case in which the holding portion is used as described above, when the fluid moves along both surfaces of the substrate, it is possible to maintain the angle formed by both surfaces of the substrate with respect to the specific direction without impairing the direction of the fluid.
In the method of forming an electroconductive substance according to the fourth aspect of the invention, the fluid is transported to the micro holes through both “flowing” and “diffusion”. Therefore, it is considered that the fluid is well transported to the micro holes compared with a case in which only one surface of the substrate is exposed to the fluid flowing toward the substrate. Therefore, according to the invention, it is possible to provide a method of forming an electroconductive substance which can deposit an electroconductive substance in the substrate at a uniform thickness.
In the method of forming an electroconductive substance according to the fourth aspect of the invention, a semiconductor substrate or a glass substrate is preferable as the substrate. When the invention is made applicable to semiconductor substrates or glass substrates, the application to the three-dimensional packaging, interposers and the like of the above-described LSI can be expected. In addition, a fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. When the fluid contains a reducing agent dissolved therein, it is possible to supply a raw material and the reducing agent to the micro holes at the same time, and it is possible to form a uniform thin film.
In the apparatus used to form an electroconductive substance according to the fifth aspect of the invention, it is possible to forcibly transport a fluid into the micro holes. Therefore, according to the invention, it is possible to provide an apparatus used to form an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
Configuration examples of the fluid introduction portion include: a case in which a pipe-shaped introduction portion is connected to the reaction chamber so as to be communicated with the first space α of the reaction chamber; a case in which the introduction portion projects in the first space α in the reaction chamber and an introduction opening is configured to be located close to the second surface of the substrate; and a case in which the introduction portion projects in the first space α in the reaction chamber and a plurality of introduction openings are configured to be located close to the second surface of the substrate.
In the apparatus used to form an electroconductive substance according to the sixth aspect of the invention, it is possible to forcibly transport a fluid into the micro holes. Therefore, according to the invention, it is possible to provide an apparatus used to form an electroconductive substance in micro holes which can deposit an electroconductive substance in micro holes provided in a substrate at a uniform thickness.
In addition, in the apparatus used to form an electroconductive substance according to the sixth aspect of the invention, since the supporting portion in which the guide path through which the fluid passes toward the second space is provided around the substrate is disposed, it is possible to reduce the load applied to the substrate. Therefore, the apparatus used to form an electroconductive substance according to the sixth aspect of the invention can prevent damage of the substrate and can prevent clogging of the pipe or the malfunction of the device.
Configuration examples of the fluid introduction portion include a case in which a pipe-shaped introduction portion is connected to the reaction chamber so as to be communicated with the first space α of the reaction chamber, a case in which the introduction portion projects in the first space α in the reaction chamber and an introduction opening is configured to be located close to the second surface of the substrate, and a case in which the introduction portion projects in the first space α in the reaction chamber and a plurality of introduction openings are configured to be located close to the second surface of the substrate.
Hereinafter, an apparatus and a method according to a first embodiment of the invention will be described.
Particularly, in the present specification, a supercritical fluid refers to a fluid in a state in which gas such as CO2 is maintained at the critical point or higher so that there is no difference between gas and liquid and the gas is neither liquid nor gas.
The apparatus is a flow-type thin film deposition apparatus, and includes a H2 tank 1, a CO2 tank 2, pressure regulators 3, a supply valve 4, a mixer 5, a liquid sending pump 6, a cooler 7, a raw material container 8, a raw material liquid sending pump 9, a front valve 10, mantle heaters 11, a preheating pipe 12, a reaction chamber 13, a back pressure regulator (BPR) 14, and a constant temperature bath 15.
In the apparatus, a supercritical or subcritical CO2 fluid is continuously supplied to the reaction chamber 13 at a constant pressure and a constant flow rate, and an electroconductive substance (for example, Cu) is precipitated and deposited on inner walls of micro holes provided in a substrate using a reducing agent H2, thereby forming a through-hole electrode.
The substance turns into gas, liquid or solid depending on temperature or pressure. The supercritical fluid refers to a substance in a state in which both the temperature and the pressure are beyond the critical point. In this state, the substance has a high density and a low viscosity, that is, has properties of both a liquid and gas. In addition, the substance has a diffusion coefficient intermediate between those of liquid and gas, and has zero (0) surface tension. Based on the above-described properties, the supercritical fluid can be said to have the same solvent power as a liquid and the same fluidity as gas. Therefore, when the supercritical fluid is used as a reaction solvent, a nano-level permeability and a high-speed reaction can be expected. In addition, depending on the conditions, there are cases in which the same actions and effects can be obtained even when a subcritical fluid is used instead of the supercritical fluid.
The H2 tank 1 contains H2 gas which is a reducing agent, and the H2 gas is introduced into the mixer 5 through the pressure regulator 3 and the supply valve 4.
The CO2 tank 2 contains CO2 gas which is a medium of the supercritical fluid, and the CO2 gas is introduced into the mixer 5 from the CO2 tank 2 after being liquefied in the cooler 7 and then pressurized in the liquid sending pump 8.
The H2 gas and the CO2 gas are mixed in the mixer 5, and are introduced into the reaction chamber 13.
The raw material container 8 contains a metal complex of an electroconductive substance which serves as a raw material. In the present embodiment, a case in which copper bis-diisobutyl methanate (Cu(dibm)2) is used will be described as an example, but the raw material is not limited thereto.
The metal complex is introduced into the reaction chamber 13 through the raw material liquid sending pump 9. The supply of the raw material is controlled using the front valve 10 provided close to a gas supply opening in the reaction chamber.
The reaction chamber 13 is preferably constituted of, for example, a pressure-resistant and heat-resistant stainless steel chamber, but the reaction chamber is not limited thereto. The reaction chamber 13 can be manufactured by, for example, working an autoclave (pressurizing and defoaming apparatus).
The preheating pipe 12 is provided in front of the reaction chamber 13, and furthermore, the preheating pipe 12 and the reaction chamber 13 are provided with the mantle heaters 11 and the constant temperature bath 15, whereby it is possible to heat and hold the flux at a predetermined temperature and to adjust the temperature.
The back pressure regulator (BPR) 14 is disposed in the downstream of the reaction chamber 13. The supercritical fluid in the reaction chamber 13 is exhausted through the back pressure regulator 14 after a reaction in the reaction chamber 13 ends.
A substrate support 31 is provided in the reaction chamber 13, and a substrate 20 is installed on the substrate support 31.
Examples of the substrate 20 that can be used include semiconductor substrates, such as silicon, and glass substrates. In addition, micro holes 21 that penetrate the substrate from a second surface toward a first surface are provided in the substrate 20.
In the above-described apparatus, a fluid, that is obtained by dissolving the metal complex in the supercritical fluid, is introduced in the reaction chamber 13, and the planar substrate 20 is disposed in the fluid which continuously moves in a specific direction in the reaction chamber 13, thereby forming an electroconductive substance on inner walls of the micro holes 21 provided in the substrate 20.
In addition, in the apparatus of the first embodiment of the invention, the reaction chamber 13 includes a first space α into which the fluid F is introduced and a second space β from which the fluid is discharged, the second surface 20a of the substrate 20 is vertical to the specific direction in which the fluid F that is introduced into the first space α moves, and the substrate support 31 (supporting portion) which supports the first surface 20b of the substrate 20 so as to make the fluid F travel toward the second surface 20a of the substrate 20 and is provided with a guide path 34 through which the fluid F is made to pass toward the second space β around the substrate 20 is disposed.
Here, there are two methods for transporting substances in a fluid, that is, “flowing” and “diffusion”. When ink dripped into water is exemplified as a fluid in order to describe the difference between “flowing” and “diffusion” using images, “flowing” has an image in which the ink has been stirred using a stick, and “diffusion” has an image in which the ink spread on its own without being stirred.
Based on the above-described consideration, in the first embodiment of the invention, apparatuses having configurations illustrated in
In any of the apparatuses illustrated in
In addition, compared with the apparatus in
That is, in the first embodiment of the invention, since the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, and the substrate 20 is configured so as to be mounted on a support member 40 including a fine communication hole provided therein, the pressure difference between the top and bottom sides of the substrate becomes large and uniform, and it is possible to forcibly transport the fluid into the micro holes. Then, in the invention, it is possible to deposit an electroconductive substance at a uniform thickness in the micro holes provided in the substrate 20.
In any of the apparatuses illustrated in
In the forcible transportation methods described above, it is considered that the pressure difference between the top and bottom sides of the substrate 20 promotes the coatability. The pressure difference is caused by a difference in the flow rate of the fluid F between the top and bottom sides of the substrate.
Furthermore, in the apparatuses of the first embodiment of the invention, the substrate support 31 (supporting portion) includes the fine communication hole through which the fluid F is made to pass toward the second space β through which the fluid F is discharged.
In the first embodiment, a glass filter is used as the supporting body including the fine communication hole therein, but the supporting body is not limited thereto. Particularly, the glass filter refers to an experimental tool equipped with a filtration filter made of a raw material of a glass fiber. GF/A refers to a highly efficient filter paper for general purposes which is widely used for the filtration of modified protein, and is also used in air pollution analyses.
When a glass filter is used as the supporting body of the substrate 20, it is considered that a space between the substrate 20 and a jig becomes small, and the pressure difference between the top and bottom surfaces of the substrate becomes large. As a result, an effect that promotes coatability can be expected.
In the first embodiment of the invention, as illustrated in
In addition to CO2, inert gases such as Ar, H2 and Xe; halogen gases such as CF4, CHF3 and CCl4; and polar gases such as NH3, CH3OH and H2O can be used as the medium of the supercritical fluid.
However, particularly in a case in which a supercritical medium is not used as a reactant, CO2 is preferable since CO2 has stability, a low impact on the environment, a low cost and solvent capability.
CO2 turns into a supercritical state at a critical temperature of 31.1° C. and a critical pressure of 7.382 MPa, which are a lower temperature and a lower pressure than those of other supercritical fluids, and is thus easy to handle. In addition, CO2 is a non-toxic and non-flammable substance that can be present in the atmosphere, and does not have any impact on the environment when being used as a reaction solvent and then exhausted in a gaseous form.
Furthermore, due to the properties of being highly diffusive and having no surface tension, CO2 is superior to other thin film-forming methods (deposition methods, sputtering, CVD and the like) in terms of being formed into a thin film on the micro holes 21. When the above-described technique is applied, ultrafine Cu wires can be produced using CO2 as an environment-friendly organic solvent.
A fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. Since the fluid contains the reducing agent dissolved therein, the entrance of the fluid into the micro holes is further promoted. In the invention, H2 is used as the reducing agent, methanol and the like can be used as the reducing agent in addition to H2.
The reaction pressure is not particularly limited, but is preferably the supercritical point or higher of the medium (7.4 MPa or more in the case of CO2), and the fluid may be in a subcritical state as long as the fluid has a good solvent capability. In the case of CO2, in order to exhibit the solvent capability, the pressure is preferably 6 MPa or more, and is set in a range of, for example, 10 MPa to 15 MPa.
In addition, the reaction temperature is preferably optimized depending on the kind of the metal complex, which is the raw material, or the reducing agent, but is not particularly limited, and can be determined in a range for which, for example, the melting point of the metal complex which is the raw material is considered as the lower limit and 400° C., which is the acceptable process temperature for integrated circuit wires, is considered as the upper limit. As the temperature increases, the film thickness also increases, but there is a tendency for the depths of the holes to decrease and become uneven.
The speed of the fluid being sprayed toward the substrate is not particularly limited; however, when the flow rate is too slow, it is difficult to reliably send the fluid into the micro holes. On the other hand, when the flow rate is too high, a strong pressure is applied to the substrate such that there is a concern that the substrate may be damaged.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1.0 ml/min or more. In order to suppress the influence of a pressure decrease during the addition of low-pressure H2 gas, the flow rate of CO2 needs at least 1.0 ml/min.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1 cm/min or more in terms of linear speed. Here, the linear speed can be obtained by, for example, dividing the volume flow rate of liquid CO2 being sent using the pump 6 by the cross-sectional area of the reaction chamber. In order to suppress the influence of a pressure change in the pump or a pressure decrease during the addition of low-pressure H2 gas, the flow rate needs at least the above value.
In addition, the reaction time is not particularly limited, and may be appropriately determined to obtain a desired film thickness.
A sequence of deposition of an electroconductive substance on the inner walls of the micro holes 21 provided in the substrate 20 using the apparatus according to the first embodiment of the invention illustrated in
(1) First, the substrate 20 is sealed in the reaction chamber 13, and the reaction chamber 13 is connected to a line of the apparatus. At this time, as illustrated in
(2) Next, all the devices except for the mantle heaters 11 and the constant temperature bath 15 are activated, and whether or not there is a leak from the reaction chamber 13 in a state in which the CO2 tank 2 and the H2 tank 2 are opened is checked (leak check).
(3) The constant temperature bath 15 and the mantle heaters 11 are activated so as to heat the flux to a set temperature.
(4) In the raw material container 8, a necessary amount of the raw material (Cu(dibm)2) for the electroconductive substance and a necessary amount of acetone are weighed and mixed.
(5) When stabilized at the set temperature, (4) is made to flow using the raw material liquid sending pump 9, and a predetermined deposition time begins to be counted. The fluid is sprayed from the nozzle toward the second surface of the substrate.
(6) During the predetermined deposition time, whether the respective devices appropriately work, such as the pressure of the H2 pressure regulator 3 and whether the raw material is reliably sent, is periodically checked.
(7) When the predetermined deposition time elapses, the raw material liquid sending pump 9 and a sequencer for supplying the reducing agent H2 are stopped, the cock of the H2 pump 1 is opened, and the CO2 liquid sending pump 6 is operated for approximately 30 minutes.
(8) The constant temperature bath 15 and the mantle heaters 11 are stopped so as to stop the heating, and the fluid is left to be naturally cooled to approximately 50° C.
(9) The CO2 pump 2 is opened, and CO2 in the apparatus is exhausted using the back pressure regulator 14.
(10) The reaction chamber 13 is removed from the line, and all the devices are turned off
(11) Finally, the substrate 20 is removed from the reaction chamber 13.
As described above, in the first embodiment of the invention, when the second surface 20a of the substrate 20 is vertical to the flow direction of the fluid, and the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, it is possible to forcibly transport the fluid into the micro holes 21, and to deposit an electroconductive substrate in the micro holes 21 at a uniform thickness.
Furthermore, in the first embodiment of the invention, it is considered that, since the substrate support 31 is provided with the fine communication hole through which the fluid passes toward the second space β, the space of the jig of the substrate 20 becomes small, and the pressure difference between the top and bottom surfaces of the substrate becomes large. As a result, it is possible to more reliably deposit an electroconductive substance in the micro holes 21.
In addition, since the substrate support 31 is provided with the fine communication hole and supports the substrate 20 throughout the entire first surface 20b, it is possible to reduce the load applied to the substrate 20. Then, it is possible to prevent the damage of the substrate 20 and to prevent the clogging of the pipe or the malfunction of the device.
Particularly, in the above-described first embodiment, a case in which the supercritical fluid is used as the medium of the fluid has been described using examples, but the invention is not limited thereto, and can also be similarly applied in a case in which a subcritical fluid is used as the medium of the fluid.
Hereinafter, a preferable embodiment of an apparatus and a method according to a second embodiment of the invention will be described.
The apparatus is a flow-type thin film deposition apparatus, and includes the H2 tank 1, the CO2 tank 2, the pressure regulators 3, the supply valve 4, the mixer 5, the liquid sending pump 6, the cooler 7, the raw material container 8, the raw material liquid sending pump 9, the front valve 10, the mantle heaters 11, the preheating pipe 12, the reaction chamber 13, the back pressure regulator (BPR) 14, and the constant temperature bath 15.
In the apparatus, a supercritical or subcritical CO2 fluid is continuously supplied to the reaction chamber 13 at a constant pressure and a constant flow rate, and an electroconductive substance (for example, Cu) is precipitated and deposited on the inner walls of the micro holes provided in the substrate using a reducing agent H2, thereby forming a through-hole electrode.
In the second embodiment of the invention, the H2 tank 1 contains H2 gas which is a reducing agent, and the H2 gas is introduced into the mixer 5 through the pressure regulator 3 and the supply valve 4.
The CO2 tank 2 contains CO2 gas which is a medium of the supercritical fluid, and the CO2 gas is introduced into the mixer 5 from the CO2 tank 2 after being liquefied in the cooler 7 and then pressurized in the liquid sending pump 8.
The H2 gas and the CO2 gas are mixed in the mixer 5, and introduced into the reaction chamber 13.
In the second embodiment of the invention, the raw material container 8 contains a metal complex of an electroconductive substance which serves as a raw material. In the second embodiment, a case in which copper bis-isobutyl methanoate (Cu(dibm)2) is used will be described as an example, but the raw material is not limited thereto.
The metal complex is introduced into the reaction chamber 13 through the raw material liquid sending pump 9. The supply of the raw material is controlled using the front valve 10 provided close to a gas supply opening in the reaction chamber.
The reaction chamber 13 is preferably constituted of, for example, a pressure-resistant and heat-resistant stainless steel chamber, but the reaction chamber is not limited thereto. The reaction chamber 13 can be manufactured by, for example, working an autoclave (pressurizing and defoaming apparatus).
The preheating pipe 12 is provided in front of the reaction chamber 13, and furthermore, the preheating pipe 12 and the reaction chamber 13 are provided with the mantle heaters 11 and the constant temperature bath 15, whereby it is possible to heat and hold the flux at a predetermined temperature and to adjust the temperature.
The back pressure regulator (BPR) 14 is disposed in the downstream of the reaction chamber 13. The supercritical fluid in the reaction chamber 13 is exhausted through the back pressure regulator 14 after a reaction in the reaction chamber 13 ends.
A base plate support is provided in the reaction chamber 13, and a substrate is installed on the base plate support.
Examples of the substrate 20 that can be used include semiconductor substrates, such as silicon, and glass substrates. In addition, the micro holes 21 are provided in the substrate 20.
In the apparatus of the second embodiment, a fluid obtained by dissolving the metal complex in the supercritical fluid is introduced in the reaction chamber 13, and the planar substrate 20 is disposed in the fluid which continuously moves in a specific direction in the reaction chamber 13, thereby forming an electroconductive substance on inner walls of the micro holes 21 provided in the substrate 20.
In addition, in the apparatus of the second embodiment of the invention, both surfaces of the substrate 20 are not parallel to the specific direction, and the substrate 20 is disposed so that the fluid moves along both surfaces of the substrate 20.
In the second embodiment as well, it is possible to schematically illustrate the positional relationship between the substrate 20 having the micro holes 21 and the flow direction of the fluid F in the reaction chamber 13 using
In the second embodiment of the invention, it is possible to deposit an electroconductive substance in the micro holes 21 at a uniform thickness. Particularly, the substrate 20 and the flow direction are preferably vertical to each other, that is, the micro holes 21 and the flow direction are preferably parallel to each other. Then, it is possible to more efficiently transport the raw material into the micro holes 21.
In addition, when the substrate 20 is disposed so that the fluid moves along both surfaces of the substrate 20, in a case in which the micro holes 21 are through holes, it is possible to transport the raw material from both sides of the micro holes 21, and to more efficiently deposit an electroconductive substance into the micro holes 21.
In the second embodiment as well, in addition to CO2, inert gases such as Ar, H2 and Xe; halogen gases such as CF4, CHF3 and CCl4; and polar gases such as NH3, CH3OH and H2O can be used.
However, particularly in a case in which a supercritical medium is not used as a reactant, CO2 is preferable since CO2 has stability, a low impact on the environment, a low cost and solvent capability.
CO2 turns into a supercritical state at a critical temperature of 31.1° C. and a critical pressure of 7.382 MPa, which are a lower temperature and a lower pressure than those of other supercritical fluids, and is thus easy to handle. In addition, CO2 is a non-toxic and non-flammable substance that can be present in the atmosphere, and does not have a higher environmental impact when being used as a reaction solvent and then exhausted in a gaseous form.
Furthermore, due to the properties of being highly diffusive and having no surface tension, CO2 is superior to other thin film-forming methods (deposition methods, sputtering, CVD and the like) in terms of being formed into a thin film on the micro holes 21. When the above-described technique is applied, ultrafine Cu wires can be produced using CO2 as an environment-friendly organic solvent.
A fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. Since the fluid contains the reducing agent dissolved therein, the entrance of the fluid into the micro holes is further promoted.
The reaction pressure is not particularly limited, but is preferably the supercritical point or higher of the medium (7.4 MPa or more in the case of CO2), and the fluid may be in a subcritical state as long as the fluid has a good solvent capability. In the case of CO2, in order to exhibit the solvent capability, the pressure is preferably 6 MPa or more, and is set in a range of, for example, 10 MPa to 15 MPa.
In addition, the reaction temperature is preferably optimized depending on the kind of the metal complex, which is the raw material, or the reducing agent, but is not particularly limited, and can be determined in a range for which, for example, the melting point of the metal complex which is the raw material is considered as the lower limit and 400° C., which is the acceptable process temperature for integrated circuit wires, is considered as the upper limit. As the temperature increases, the film thickness also increases, but there is a tendency for the depths of the holes to decrease and become uneven.
In addition, the reaction time is not particularly limited, and may be appropriately determined to obtain a desired film thickness.
A sequence of deposition of an electroconductive substance on the inner walls of the micro holes 21 provided in the substrate 20 using the apparatus illustrated in
(1) First, the substrate 20 is sealed in the reaction chamber 13, and the reaction chamber 13 is connected to a line of the apparatus. At this time, both surfaces of the substrate 20 are not parallel to the flow direction of the fluid, and the substrate 20 is disposed so that the fluid moves along both surfaces of the substrate 20.
(2) Next, all the devices except for the mantle heaters 11 and the constant temperature bath 15 are activated, and whether or not there is a leak from the reaction chamber 13 in a state in which the CO2 tank 2 and the H2 tank 2 are opened is checked (leak check).
(3) The constant temperature bath 15 and the mantle heaters 11 are activated so as to heat the flux to a set temperature.
(4) In the raw material container 8, the necessary amount of the raw material (Cu(dibm)2) for the electroconductive substance and the necessary amount of acetone are weighed and mixed.
(5) When stabilized at the set temperature, (4) is made to flow using the raw material liquid sending pump 9, and a predetermined deposition time begins to be counted.
(6) During the predetermined deposition time, whether the respective devices appropriately work, such as the pressure of the H2 pressure regulator 3 and whether the raw material is reliably sent, is periodically checked.
(7) When the predetermined deposition time elapses, the raw material liquid sending pump 9 and a sequencer for supplying the reducing agent H2 are stopped, the cock of the H2 pump 1 is opened, and the CO2 liquid sending pump 6 is operated for approximately 30 minutes.
(8) The constant temperature bath 15 and the mantle heaters 11 are stopped so as to stop the heating, and the fluid is left to be naturally cooled to approximately 50° C.
(9) The CO2 pump 2 is opened, and CO2 in the apparatus is exhausted using the back pressure regulator 14.
(10) The reaction chamber 13 is removed from the line, and all the devices are turned off.
(11) Finally, the substrate 20 is removed from the reaction chamber 13.
As described above, in the second embodiment of the invention, when the substrate 20 is disposed so that both surfaces thereof are not parallel to the flow direction of the fluid, it is possible to deposit an electroconductive substrate in the micro holes 21 at a uniform thickness. Particularly, the substrate 20 and the flow direction are preferably vertical to each other, that is, the micro holes 21 and the flow direction are preferably are parallel to each other. Then, it is possible to more efficiently transport the raw material into the micro holes 21.
Particularly, in the above-described second embodiment, a case in which the supercritical fluid is used as the medium of the fluid has been described using examples, but the invention is not limited thereto, and can also be similarly applied in a case in which a subcritical fluid is used as the medium of the fluid.
Hereinafter, an apparatus and a method according to a third embodiment of the invention will be described.
The apparatus of the third embodiment can be described using an apparatus having the same configuration as the apparatus of
The substrate support 31 is provided in the reaction chamber 13, and the substrate 20 is installed on the substrate support 31.
Examples of the substrate 20 that can be used include semiconductor substrates, such as silicon, and glass substrates. In addition, the micro holes 21 that penetrate the substrate from the second surface toward the first surface are provided in the substrate 20.
In the apparatus of the third embodiment, a fluid obtained by dissolving the metal complex in the supercritical fluid is introduced in the reaction chamber 13, and the planar substrate 20 is disposed in the fluid which continuously moves in a specific direction in the reaction chamber 13, thereby forming an electroconductive substance on inner walls of the micro holes 21 provided in the substrate 20.
In addition, in the apparatus of the third embodiment, the reaction chamber 13 includes the first space α into which the fluid is introduced and the second space β from which the fluid is discharged, the second surface 20a of the substrate 20 is vertical to the specific direction in which the fluid F that is introduced into the first space moves, and the first surface 20b of the substrate is supported so as to make the fluid travel in the micro holes 21 in the substrate 20 toward the first surface 20b from the second surface 20a of the substrate.
In the third embodiment as well, it is possible to schematically illustrate the positional relationship between the substrate 20 having the micro holes 21 and the flow direction of the fluid F in the reaction chamber 13 using
In the third embodiment, apparatuses having configurations illustrated in
In any of the apparatuses illustrated in
In addition, compared with the apparatus in
That is, in the third embodiment of the invention, since the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, it is possible to forcibly transport the fluid into the micro holes. Then, in the third embodiment of the invention, it is possible to deposit an electroconductive substance in the micro holes provided in the substrate 20 at a uniform thickness.
In any of the apparatuses illustrated in
In addition, in order to stably support the substrate 20, the reaction chamber 13 was made to stand vertically as illustrated in
In addition to CO2, inert gases such as Ar, H2 and Xe; halogen gases such as CF4, CHF3 and CCl4; and polar gases such as NH3, CH3OH and H2O can be used as the medium of the supercritical fluid.
However, particularly in a case in which a supercritical medium is not used as a reactant, CO2 is preferable since CO2 has stability, a low environmental impact, a low cost and solvent capability.
CO2 turns into a supercritical state at a critical temperature of 31.1° C. and a critical pressure of 7.382 MPa, which are a lower temperature and a lower pressure than those of other supercritical fluids, and is thus easy to handle. In addition, CO2 is a non-toxic and non-flammable substance that can be present in the atmosphere, and does not cause any environmental load when being used as a reaction solvent and then exhausted in a gaseous form.
Furthermore, due to the properties of being highly diffusive and having no surface tension, CO2 is superior to other thin film-forming methods (deposition methods, sputtering, CVD and the like) in terms of being formed into a thin film on the micro holes 21. When the above-described technique is applied, ultrafine Cu wires can be produced using CO2 as an environment-friendly organic solvent.
A fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. Since the fluid contains the reducing agent dissolved therein, the entrance of the fluid into the micro holes is further promoted. In the invention, H2 is used as the reducing agent, methanol and the like can be used as the reducing agent in addition to H2.
The reaction pressure is not particularly limited, but is preferably the supercritical point or higher of the medium (7.4 MPa or more in the case of CO2), and the fluid may be in a subcritical state as long as the fluid has a good solvent capability. In the case of CO2, in order to exhibit the solvent capability, the pressure is preferably 6 MPa or more, and is set in a range of, for example, 10 MPa to 15 MPa.
In addition, the reaction temperature is preferably optimized depending on the kind of the metal complex, which is the raw material, or the reducing agent, but is not particularly limited, and can be determined in a range for which, for example, the melting point of the metal complex which is the raw material is considered as the lower limit and 400° C., which is the acceptable process temperature for integrated circuit wires, is considered to be the upper limit. As the temperature increases, the film thickness also increases, but there is a tendency for the depths of the holes to decrease and become uneven.
The speed of the fluid being sprayed toward the substrate is not particularly limited; however, when the flow rate is too slow, it is difficult to reliably send the fluid into the micro holes. On the other hand, when the flow rate is too high, a strong pressure is applied to the substrate such that there is a concern that the substrate may be damaged.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1.0 ml/min or more. In order to suppress the influence of a pressure decrease during the addition of low-pressure H2 gas, the flow rate of CO2 needs at least 1.0 ml/min.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1 cm/min or more in terms of linear speed. Here, the linear speed can be obtained by, for example, dividing the volume flow rate of liquid CO2 being sent using the pump 6 by the cross-sectional area of the reaction chamber. In order to suppress the influence of a pressure change in the pump or a pressure decrease during the addition of low-pressure H2 gas, the flow rate needs at least the above-described value.
In addition, the reaction time is not particularly limited, and may be appropriately determined in order to obtain a desired film thickness.
Since the sequence of deposition of an electroconductive substance on the inner walls of the micro holes 21 provided in the substrate 20 in the third embodiment of the invention is the same as in the first embodiment, the sequence will not be described here.
In the third embodiment of the invention, when the second surface 20a of the substrate 20 is vertical to the flow direction of the fluid, and the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, it is possible to forcibly transport the fluid into the micro holes 21, and to deposit an electroconductive substrate in the micro holes 21 at a uniform thickness.
Particularly, in the above-described third embodiment, a case in which the supercritical fluid is used as the medium of the fluid has been described using examples, but the invention is not limited thereto, and can also be similarly applied in a case in which a subcritical fluid is used as the medium of the fluid.
Hereinafter, an apparatus and a method according to a fourth embodiment of the invention will be described.
The apparatus of the fourth embodiment can be described using the apparatus of
The substrate support 31 is provided in the reaction chamber 13, and the substrate 20 is installed on the substrate support 31.
Examples of the substrate 20 that can be used include semiconductor substrates, such as silicon, and glass substrates. In addition, the micro holes 21 that penetrate the substrate from the second surface toward the first surface are provided in the substrate 20.
In the apparatus, a fluid obtained by dissolving the metal complex in the supercritical fluid is introduced in the reaction chamber 13, and the planar substrate 20 is disposed in the fluid which continuously moves in a specific direction in the reaction chamber 13, thereby forming an electroconductive substance on inner walls of the micro holes 21 provided in the substrate 20.
In addition, in the apparatus of the fourth embodiment of the invention, the reaction chamber 13 includes the first space α into which the fluid is introduced and the second space β from which the fluid is discharged, the second surface 20a of the substrate 20 is vertical to the specific direction in which the fluid F that is introduced into the first space moves, the first surface 20b of the substrate 20 is supported so as to make the fluid travel in the micro holes of the substrate 20 toward the second surface 20a, and the substrate support 31 (support member) including the guide path 34 through which the fluid F is made to pass toward the second space β provided around the substrate 20 is disposed.
In the fourth embodiment as well, it is possible to schematically illustrate the positional relationship between the substrate 20 having the micro holes 21 and the flow direction of the fluid F in the reaction chamber 13 using
In the fourth embodiment, an apparatus having a configuration illustrated in
Particularly, similarly to the third embodiment, the fourth embodiment of the invention will be described below using
In any of the apparatuses illustrated in
In addition, compared with the apparatus in
That is, in the fourth embodiment of the invention, since the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, it is possible to forcibly transport the fluid into the micro holes. Then, in the invention, it is possible to deposit an electroconductive substance in the micro holes provided in the substrate 20 at a uniform thickness.
In any of the apparatuses illustrated in
In addition, in order to stably support the substrate 20, the reaction chamber 13 was made to stand vertically as illustrated in
Furthermore, in the apparatus of the fourth embodiment of the invention, the substrate support 31 (supporting portion) includes the guide path through which the fluid passes toward the second space β through which the fluid F is discharged provided around the substrate 20.
When the substrate 20 is attached to the substrate support 31 so as to become vertical to the flow direction of the fluid F, in a case in which the apparatus is configured so that the fluid is forcibly transported only into the micro holes 21 using an O ring 32 that is small enough to be accommodated in the rear surface of the substrate 20, a load is applied to places at which the substrate 20 is supported, and there is a concern that the substrate 20 may be broken. Furthermore, there is a probability that, when broken glass enters the line, the pipe may be clogged or the device may be malfunctioned.
Therefore, in the fourth embodiment of the invention, the O ring 32 that supported the rear surface of the substrate 20 and was larger than the rear surface as illustrated in
In addition to CO2, inert gases such as Ar, H2 and Xe; halogen gases such as CF4, CHF3 and CCl4; and polar gases such as NH3, CH3OH and H2O can be used as the medium of the supercritical fluid.
However, particularly in a case in which a supercritical medium is not used as a reactant, CO2 is preferable since CO2 has stability, a low environmental impact, a low cost and solvent capability.
CO2 turns into a supercritical state at a critical temperature of 31.1° C. and a critical pressure of 7.382 MPa, which are a lower temperature and a lower pressure than those of other supercritical fluids, and is thus easy to handle. In addition, CO2 is a non-toxic and non-flammable substance that can be present in the atmosphere, and does not cause any environmental load when being used as a reaction solvent and then exhausted in a gaseous form.
Furthermore, due to the properties of being highly diffusive and having no surface tension, CO2 is superior to other thin film-forming methods (deposition methods, sputtering, CVD and the like) in terms of being formed into a thin film on the micro holes 21. When the above-described technique is applied, ultrafine Cu wires can be produced using CO2 as an environment-friendly organic solvent.
A fluid further containing a reducing agent dissolved as an additional gas is desirably used as the fluid. Since the fluid contains the reducing agent dissolved therein, the entrance of the fluid into the micro holes is further promoted. In the invention, H2 is used as the reducing agent, methanol and the like can be used as the reducing agent in addition to H2.
The reaction pressure is not particularly limited, but is preferably the supercritical point or higher of the medium (7.4 MPa or more in the case of CO2), and the fluid may be in a subcritical state as long as the fluid has a good solvent capability. In the case of CO2, in order to exhibit the solvent capability, the pressure is preferably 6 MPa or more, and is in a range of for example, 10 MPa to 15 MPa.
In addition, the reaction temperature is preferably optimized depending on the kind of the metal complex, which is the raw material, or the reducing agent, but is not particularly limited, and can be determined to be in a range for which, for example, the melting point of the metal complex which is the raw material is considered as the lower limit and 400° C., which is the acceptable process temperature for integrated circuit wires, is considered to be the upper limit. As the temperature increases, the film thickness also increases, and there is a tendency for the depths of the holes to decrease and become uneven.
The speed of the fluid being sprayed toward the substrate is not particularly limited; however, when the flow rate is too slow, it is difficult to reliably send the fluid into the micro holes. On the other hand, when the flow rate is too high, a strong pressure is applied to the substrate such that there is a concern that the substrate may be damaged.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1.0 ml/min or more. In order to suppress the influence of a pressure decrease during the addition of low-pressure H2 gas, the flow rate of CO2 needs at least 1.0 ml/min.
Particularly, the flow rate of CO2 which is the medium of the fluid is preferably 1 cm/min or more in terms of linear speed. Here, the linear speed can be obtained by, for example, dividing the volume flow rate of liquid CO2 being sent using the pump 6 by the cross-sectional area of the reaction chamber. In order to suppress the influence of a pressure change in the pump or a pressure decrease during the addition of low-pressure H2 gas, the flow rate needs at least the above-described value.
In addition, the reaction time is not particularly limited, and may be appropriately determined to obtain a desired film thickness.
Since a sequence of deposition of an electroconductive substance on the inner walls of the micro holes 21 provided in the substrate 20 in the fourth embodiment of the invention is the same as in the first embodiment, the sequence will not be described.
In the fourth embodiment of the invention, when the second surface 20a of the substrate 20 is vertical to the flow direction of the fluid, and the substrate 20 is disposed so that the fluid F travels toward the second surface 20a of the substrate 20, it is possible to forcibly transport the fluid into the micro holes 21, and to deposit an electroconductive substrate in the micro holes 21 at a uniform thickness.
Furthermore, in the fourth embodiment of the invention, since the substrate support 31 includes the guide path 34 through which the fluid passes toward the second space β provided around the substrate 20, it is possible to reduce the load applied to the substrate 20. Then, it is possible to prevent the damage of the substrate 20 and to prevent the clogging of the pipe or the malfunction of the device.
Particularly, in the above-described fourth embodiment, a case in which the supercritical fluid is used as the medium of the fluid has been described using examples, but the invention is not limited thereto, and can also be similarly applied in a case in which a subcritical fluid is used as the medium of the fluid.
Hereinafter, examples carried out for confirming the effect of a second embodiment of the invention will be described.
Particularly, in the present example, the configuration of the apparatus according to the second embodiment of the invention was used.
An electroconductive substance was deposited on inner walls of micro holes provided in a substrate using an apparatus illustrated in
A fluid obtained by dissolving a supercritical CO2 fluid as a medium, Cu(dibm)2 as a metal complex, and H2 gas as a reducing agent was used as the fluid. The concentration of Cu(dibm)2 in the fluid was 2.92×10−2 mol % (273 K), and the concentration of the H2 gas in the fluid was 1.53 mol % (273 K).
A glass substrate (SiO2) including micro holes in the central portion was used as the substrate. The micro hole had a diameter of 30 μm and a depth of 310 μm.
In the reaction chamber, the substrate 20 was disposed so that both surfaces thereof (the top and bottom surfaces) are exposed to a fluid F so as not to be parallel to the flow direction of the fluid F, and an electroconductive substance was deposited on the inner walls of the micro holes. Here, the substrate was disposed to be approximately vertical to the flow direction of the fluid (disposition in
In the present example as well, the configuration of the apparatus of the second embodiment of the invention was used.
In the reaction chamber, the substrate 20 was disposed so that both surfaces thereof (the top and bottom surfaces) are exposed to a fluid F so as to be parallel to the flow direction of the fluid F, and an electroconductive substance was deposited on the inner walls of the micro holes. Here, the substrate was disposed to be approximately vertical to the flow direction of the fluid (disposition in
In the present comparative example, the configuration of the apparatus of the second embodiment of the invention was used.
In the reaction chamber, the substrate 20 was disposed so that a second surface thereof (top surface) is only exposed to a fluid F so as to be parallel to the flow direction of the fluid F and a first surface thereof (bottom surface) is in contact with an inner surface of the reaction chamber 13, and an electroconductive substance was deposited on the inner walls of the micro holes. Particularly, the reaction pressure was 10 MPa, the reaction temperature was 280° C., and the reaction time was 240 min (disposition in
The cross-sections of the substrates obtained in the above-described manner were observed. In addition, the film thicknesses of the deposited electroconductive substances were measured.
The film thicknesses were measured using a micrometer and observed using an optical microscope.
The substrate was cut into halves using a diamond cutter. At this time, an adhesive was applied to the surface of a cut piece. The adhesive was applied in order to prevent the intrusion of debris into the micro holes during the polishing of the cross-section. After the adhesive was dried, the cross-section was polished using sandpaper (#1500 to #10000) while observing the cross-section using the optical microscope, and the cross-section of the substrate was observed using the optical microscope.
An optical microscopic photograph of a cross-section of the substrate of the first example is illustrated in
In a specimen of the comparative example, a Cu film was formed in the micro holes only from the second surface (top surface) of the substrate, but the depth of the formed Cu film from the inlet of the micro hole was approximately the same (30 μm) as the diameter of the micro hole. Therefore, in the case of the comparative example, the aspect ratio was approximately 1.
In contrast to the comparative example, in the first example illustrated in
In addition, in the second example illustrated in
The film thickness was also 5.6 μm on the surface of the substrate and 1.4 μm in the central portion of the hole, which indicates that the film thickness was not uniform, but it is found that the Cu film can be sufficiently formed in the micro holes compared with in the first comparative example. In the case of the second example, the aspect ratio was in a range of approximately 4 to 5 (=135/30).
From the above-described results, it has been clarified that, when the substrate 20 is disposed so that both surfaces thereof (the top and bottom surfaces) are exposed to the fluid F so as to be parallel to or so as not to be parallel to the flow direction of the fluid F, it is possible to deposit an electroconductive substance on the inside of the micro holes. Particularly, it was confirmed that, when the substrate is disposed so as not to be parallel to the flow direction of the fluid, it is possible to deposit an electroconductive substance at a uniform thickness on the inside of the micro holes.
This is considered to be because the fluid was transported to the micro holes through both “flowing” and “diffusion” so that it was possible to more efficiently transport the raw material inside the micro holes.
In addition, when the substrate was disposed so as to make the fluid move along both surfaces of the substrate, it was possible to transport the raw material from both sides of the micro holes, and to more efficiently deposit an electroconductive substance in the micro holes.
In the present example, the configuration of the apparatus of a third embodiment of the invention was used.
An electroconductive substance was deposited on the inner walls of the micro holes provided in the substrate using the apparatus illustrated in
A fluid obtained by dissolving a supercritical CO2 fluid as a medium, (Cu(dibm)2) as a metal complex which serves as the raw material of the electroconductive substance, and H2 gas as a reducing agent was used as the fluid. Particularly, the fluid contains the metal complex dissolved at a ratio of 500/25 using acetone as an auxiliary solvent.
The concentration of (Cu(dibm)2) in the fluid was 2.92×10−2 mol % (273 K), and the concentration of the H2 gas in the fluid was 1.53 mol % (273 K).
A glass substrate (SiO2) which included micro holes that vertically penetrated the substrate between both principal surfaces in the central portion and had a plate thickness of 0.75 mm (750 μm) as illustrated in
In the reaction chamber, the substrate was disposed to be vertical to the flow direction of the fluid, and the bottom surface of the substrate was sealed using a support member made of an O ring. In addition, an electroconductive substance was deposited on the inner walls of the micro holes by spraying the fluid from the nozzle toward the second surface of the substrate.
Particularly, the reaction pressure was 10 MPa in total pressure (a H2 gas pressure of 1 MPa), the reaction temperature was 280° C., the flow rate of CO2 was 7.0 ml/min, and the reaction time was 60 min.
In the present comparative example, the configuration of the apparatus of the third embodiment of the invention was used.
The specification of the reaction chamber and the specification of the substrate were changed as described below, and an electroconductive substance was deposited on the inner walls of the micro holes.
A reaction chamber illustrated in
In the reaction chamber, the substrate 20 was disposed so that both surfaces thereof (the top and bottom surfaces) are exposed to a fluid F so as not to be parallel to the flow direction of the fluid F, and an electroconductive substance was deposited on the inner walls of the micro holes. Herein, the substrate was disposed so as to be substantially vertical to the flow direction of the fluid (disposition in
A glass substrate (SiO2) which included micro holes that vertically penetrated the substrate between both principal surfaces in the central portion and had a plate thickness of 0.30 mm (300 μm) was used as the substrate. The micro hole had a diameter of 30 μm.
The cross-sections of the substrates obtained in the above-described manner were observed using an optical microscope.
The substrate was cut into halves using a diamond cutter. At this time, an adhesive was applied to the surface of a cut piece. The adhesive was applied in order to prevent the intrusion of debris into the micro holes during the polishing of the cross-section. After the adhesive was dried, the cross-section was polished using sandpaper (#1500 to #10000) while observing the cross-section using the optical microscope, and the cross-section of the substrate was observed using the optical microscope.
It was found that, under the conditions of the second comparative example, the electroconductive substance was evenly deposited at a uniform thickness throughout the entire area of the micro hole in the longitudinal direction. It was confirmed that, in a case in which the diameter of the micro holes was 30 μm in the glass substrate (SiO2) having a plate thickness of 0.30 mm (300 μm), it was possible to reliably form an electroconductive substance on the inner walls of the micro holes without using the apparatus used to form an electroconductive substance according to the invention (
Regarding the configuration of the apparatus of the third embodiment of the invention, the following facts were clarified from the above-described examples and comparative examples.
(1) In a case in which the hole diameter of the micro hole is in a range of approximately 25 μm to 30 μm, when the substrate is disposed so as to be vertical to the flow direction of the fluid, it is possible to deposit an electroconductive substance at a uniform thickness up inside the micro holes.
(2) When a configuration of the apparatus in which the first space α located on the fluid inlet side of the micro hole in the substrate has a higher pressure than the second space β located on the fluid outlet side of the micro hole (
(3) With the configuration of the apparatus illustrated in
From the above-described results, it was confirmed that, according to the third embodiment of the invention, when the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and the first surface of the substrate is supported so that the fluid travels in the micro holes of the substrate from the second surface toward the first space of the substrate, it is possible to deposit an electroconductive substance at a uniform thickness up inside micro holes with an aspect ratio of 30.
When a configuration of the apparatus in which the pressure becomes higher on the second surface side of the substrate than in the first surface side of the substrate was employed, the effect that forcibly transports the fluid inside the micro holes improved, and it was possible to efficiently deposit an electroconductive substance on the inside of the micro holes with a high aspect ratio.
Particularly, when a configuration in which the fluid introduction portion is made to project in the first space of the reaction chamber and an introduction opening is located close to the second surface of the substrate or a configuration in which the introduction portion is made to project in the first space of the reaction chamber and a plurality of introduction openings are located close to the second surface of the substrate, the above-described actions and effects are further intensified. For example, in a case in which the former configuration is employed, when the fluid introduction portion is disposed at a location opposite to the inlet of the micro hole, it is possible to increase the inflow amount of the fluid being forcibly transported into the micro holes, which is preferable. On the other hand, the latter configuration can be effectively applied to substrates having a plurality of micro holes due to an increase in the area of the substrate. It is possible to forcibly transport the fluid inside each of a plurality of micro holes in a uniform manner.
Thus far, the apparatus and method of the third embodiment of the invention have been described, but the invention is not limited thereto, and appropriate modification can be made within the scope of the purpose of the invention. In addition, the third embodiment of the invention has an object of “providing an apparatus and a method of forming an electroconductive substance in micro holes which can deposit an electroconductive substance at a uniform thickness in micro holes provided in a substrate”, but an electroconductive substance may be deposited in micro holes and on the surface of the substrate.
In the present example, the configuration of the apparatus of a fourth embodiment of the invention was used.
An electroconductive substance was deposited on the inner walls of the micro holes provided in the substrate using the apparatus illustrated in
A fluid obtained by dissolving a supercritical CO2 fluid as a medium, (Cu(dibm)2) as a metal complex which serves as the raw material of the electroconductive substance, and H2 gas as a reducing agent was used as the fluid. Particularly, the fluid contains the metal complex dissolved at a ratio of 500/25 using acetone as an auxiliary solvent.
The concentration of (Cu(dibm)2) in the fluid was 2.92×10−2 mol % (273 K), and the concentration of the H2 gas in the fluid was 1.53 mol % (273 K).
A glass substrate (SiO2) which included micro holes that vertically penetrated the substrate between both principal surfaces in the central portion as illustrated in
In the reaction chamber, the substrate was disposed to be vertical to the flow direction of the fluid, and the bottom surface of the substrate was sealed using a support member made of an O ring. In addition, an electroconductive substance was deposited on the inner walls of the micro holes by spraying the fluid from the nozzle toward the second surface of the substrate.
Particularly, the reaction pressure was 10 MPa in total pressure (a H2 gas pressure of 1 MPa), the reaction temperature was 200° C., the flow rate of CO2 was 2.0 ml/min, and the reaction time was 60 min.
In the present example, the configuration of the apparatus of a fourth embodiment of the invention was used.
An electroconductive substance was deposited on the inner walls of the micro holes under the same production conditions as in the fourth example except for the fact that the substrate was changed according to a specification described below.
In the example, a glass substrate (SiO2) which included a plurality (reference sings a to g) of micro holes provided in a substrate in a curved shape as illustrated in
In the present comparative example, the configuration of the apparatus of the fourth embodiment of the invention was used.
The specification of the reaction chamber was changed as described below, and an electroconductive substance was deposited on the inner walls of the micro holes.
The same reaction chamber as in the fourth example except for the fact that an O ring smaller than the substrate was used in the configuration illustrated in
That is, a configuration in which the fluid flowing from the first space α toward the second space β passes through only the micro holes provided the substrate was provided by supporting the first surface 20b side of the substrate 20 using the O ring 32.
In the present comparative example, the configuration of the apparatus of the fourth embodiment of the invention was used.
The specifications of the reaction chamber and the specifications of the substrate were changed as described below, and an electroconductive substance was deposited on the inner walls of the micro holes.
The same reaction chamber as in the fourth example except for the fact that an O ring smaller than the substrate was used in the configuration illustrated in
The same substrate as in the fifth example was used as the substrate. That is, a glass substrate (SiO2) which included a plurality (reference sings a to g) of micro holes provided in a substrate in a curved shape as illustrated in
The cross-sections of the substrates obtained in the above-described manner were observed using an optical microscope.
The substrate was cut into halves using a diamond cutter. At this time, an adhesive was applied to the surface of a cut piece. The adhesive was applied in order to prevent the intrusion of debris into the micro holes during the polishing of the cross-section. After the adhesive was dried, the cross-section was polished using sandpaper (#1500 to #10000) while observing the cross-section using the optical microscope, and the cross-section of the substrate was observed using the optical microscope.
In the fifth example, in the substrate illustrated in
Under the conditions of the third comparative example, the electroconductive substance can be only deposited until up to a location at an approximately half depth of the micro hole as seen from the inlet.
Under the conditions of the fourth comparative example, the electroconductive substance can be only deposited until up to a location near the inlet of the micro hole, that is, up to a depth as large as the hole diameter.
The following facts were clarified from the results of examples and comparative examples in which the apparatus of the fourth embodiment of the invention had been used.
(1) In a case in which the hole diameter of the micro hole is approximately 20 μm, when a configuration of the apparatus in which the substrate is disposed so as to be vertical to the flow direction of the fluid, and the first space α located on the fluid inlet side of the micro hole in the substrate has a higher pressure than the second space β located on the fluid outlet side of the micro hole (
(2) In the substrate, when the micro hole having various longitudinal directions includes one curved portion (crank portion), it is possible to allow the fluid to flow into the micro hole up to an area beyond the curved portion (crank portion). When the micro hole includes two or more curved portions (crank portions), the method according to the invention has limitations.
(3) With the configuration of the apparatus illustrated in
From the above-described result, it was confirmed that, according to the fourth embodiment of the invention, when the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and the first surface of the substrate is supported so that the fluid travels in the micro holes of the substrate from the second surface toward the first space of the substrate, it is possible to deposit an electroconductive substance of a uniform thickness up inside micro holes with an aspect ratio of 50. In addition, it was found that, even when the curved portion (crank portion) is present in the micro holes, it is possible to deposit an electroconductive substance up to an area beyond the curved portion (crank portion).
In addition, according to the fourth embodiment of the invention, when a configuration in which a higher pressure was set on the second surface side of the substrate than on the first surface side of the substrate so that a fluid moving from the first space α toward the second space β passed through the micro holes provided in the substrate and a space (guide path) provided between the substrate and the support member made of an O ring was employed, a problem in which a load was applied to the supported portions of the substrate, the substrate was broken, and the broken substrate intruded into the line so as to clog the pipe or to malfunction the device was also solved.
Particularly, when a configuration in which the fluid introduction portion is made to project in the first space of the reaction chamber and an introduction opening is located close to the second surface of the substrate or a configuration in which the introduction portion is made to project in the first space of the reaction chamber and a plurality of introduction openings are located close to the second surface of the substrate, the above-described actions and effects are further intensified. For example, in a case in which the former configuration is employed, when the fluid introduction portion is disposed at a location opposite to the inlet of the micro hole, it is possible to increase the inflow amount of the fluid being forcibly transported into the micro holes, which is preferable. On the other hand, the latter configuration can be effectively applied to substrates having a plurality of micro holes due to an increase in the area of the substrate. It is possible to forcibly transport the fluid inside each of a plurality of micro holes in a uniform manner.
Hereinafter, examples carried out to confirm the effects of the first embodiment of the invention will be described.
In the following examples, the configuration of the apparatus according to the first embodiment of the invention was used.
In the present examples, the configuration of the apparatus according to the first embodiment of the invention was used.
An electroconductive substance was deposited on the inner walls of the micro holes provided in the substrate using the apparatus illustrated in
A fluid obtained by dissolving a supercritical CO2 fluid as a medium, (Cu(dibm)2) as a metal complex which serves as the raw material of the electroconductive substance, and H2 gas as a reducing agent was used as the fluid. Particularly, the fluid contains the metal complex dissolved at a ratio of 500/25 using acetone as an auxiliary solvent.
The concentration of (Cu(dibm)2) in the fluid was 2.92×10−2 mol % (273 K), and the concentration of the H2 gas in the fluid was 1.53 mol % (273 K).
A glass substrate (SiO2) which included micro holes that vertically penetrated the substrate between both principal surfaces in the central portion as illustrated in
In the reaction chamber, the substrate was disposed to be vertical to the flow direction of the fluid, and the substrate support (support member) 40 that holds the substrate was disposed and sealed throughout the entire bottom surface of the substrate.
A glass filter (GF/A) including the communication hole 41 was used as the substrate support (support member) 40 that holds the substrate. GF/A refers to a highly efficient filter paper for general purposes which is widely used for the filtration of modified protein, and is also used in air pollution analyses. The size of GF/A is 4.7 cm, the particle retention capacity is 1.6 μm, the load is strong, and the filtration rate (fast basis weight) is 53 g/m2.
In addition, an electroconductive substance was deposited on the inner walls of the micro holes by spraying the fluid from the nozzle toward the second surface of the substrate. Particularly, the reaction pressure was 10 MPa in total pressure (a H2 gas pressure of 1 MPa), the reaction temperature was 200° C., the flow rate of CO2 was 2.0 ml/min, and the reaction time was 60 min.
In the present example, the configuration of the apparatus of the first embodiment of the invention was used.
An electroconductive substance was deposited on the inner walls of the micro holes under the same production conditions as in the sixth example except for the fact that the substrate was changed according to a specification described below.
In the example, a glass substrate (SiO2) which included a plurality (reference sings a to g) of micro holes provided in a substrate in a curved shape as illustrated in
In the present comparative example, the configuration of the apparatus of the first embodiment of the invention was used.
The specification of the reaction chamber was changed as described below in the same manner as in the third comparative example, and an electroconductive substance was deposited on the inner walls of the micro holes.
The same reaction chamber as in the sixth example except for the fact that an O ring smaller than the substrate was used in the configuration illustrated in
In the present comparative example, the configuration of the apparatus of the first embodiment of the invention was used.
The specification of the reaction chamber and the specification of the substrate were changed as described below in the same manner as in the fourth comparative example, and an electroconductive substance was deposited on the inner walls of the micro holes.
The same reaction chamber as in the fourth example except for the fact that an O ring smaller than the substrate was used in the configuration illustrated in
The same substrate as in the fifth example was used as the substrate. That is, a glass substrate (SiO2) which included a plurality (reference sings a to g) of micro holes provided in a substrate in a curved shape as illustrated in
The cross-sections of the substrates obtained in the above-described manner were observed using an optical microscope.
The substrate was cut into halves using a diamond cutter. At this time, an adhesive was applied to the surface of a cut piece. The adhesive was applied in order to prevent the intrusion of debris into the micro holes during the polishing of the cross-section. After the adhesive was dried, the cross-section was polished using sandpaper (#1500 to #10000) while observing the cross-section using the optical microscope, and the cross-section of the substrate was observed using the optical microscope.
In the seventh example, in the substrate illustrated in
Under the conditions of the fifth comparative example, the electroconductive substance can be only deposited until up to a location at an approximately half depth of the micro hole as seen from the inlet.
Under the conditions of the sixth comparative example, the electroconductive substance can be only deposited until up to a location near the inlet of the micro hole, that is, up to a depth as large as the hole diameter.
The following facts were clarified from the results of examples and comparative examples in which the apparatus of the first embodiment of the invention had been used.
(1) In a case in which the hole diameter of the micro hole is approximately 15 μm, when a configuration of the apparatus in which the substrate is disposed so as to be vertical to the flow direction of the fluid, and the first space α located on the fluid inlet side of the micro hole in the substrate has a higher pressure than the second space β located on the fluid outlet side of the micro hole (
(2) In the substrate, when the micro hole having various longitudinal directions includes one curved portion (crank portion), it is possible to allow the fluid to flow into the micro hole up to an area beyond the curved portion (crank portion). Even when the micro hole includes two or more curved portions (crank portions), according to the method of the invention, it is possible to make the fluid travel throughout the entire areas of the micro holes in the longitudinal direction.
(3) The configuration of the apparatus illustrated in
From the above-described result, it was confirmed that, according to the first embodiment of the invention, when the second surface of the substrate is vertical to the specific direction in which the fluid that is introduced into the first space moves and the first surface of the substrate is supported so that the fluid travels in the micro holes of the substrate from the second surface toward the first space of the substrate, it is possible to deposit an electroconductive substance at a uniform thickness up inside micro holes with an aspect ratio of 100. In addition, it was found that, even when the curved portion (crank portion) is present in the micro hole, it is possible to deposit an electroconductive substance up to an area beyond the curved portion (crank portion).
In addition, according to the first embodiment of the invention, when a configuration in which a higher pressure was set on the second surface side of the substrate than on the first surface side of the substrate so that a fluid moving from the first space α toward the second space β passed through the micro holes provided in the substrate and the fine communication hole included in the support member that mounted the substrate so as to be supplied to the micro holes from the first surface side of the substrate was employed, a problem in which a load was applied to the supported portions of the substrate, the substrate was broken, and the broken substrate intruded into the line so as to clog the pipe or to malfunction the device was also solved.
Particularly, when a configuration in which the fluid introduction portion is made to project in the first space of the reaction chamber and an introduction opening is located close to the second surface of the substrate or a configuration in which the introduction portion is made to project in the first space of the reaction chamber and a plurality of introduction openings are located close to the second surface of the substrate, the above-described actions and effects are further intensified. For example, in a case in which the former configuration is employed, when the fluid introduction portion is disposed at a location opposite to the inlet of the micro hole, it is possible to increase the inflow amount of the fluid being forcibly transported into the micro holes, which is preferable. On the other hand, the latter configuration can be effectively applied to substrates having a plurality of micro holes due to an increase in the area of the substrate. It is possible to forcibly transport the fluid inside each of a plurality of micro holes in a uniform manner.
Thus far, the apparatus and method of the invention have been described, but the invention is not limited thereto, and appropriate modifications can be made within the scope of the purpose of the invention.
The invention can be widely applied to an apparatus and a method of forming an electroconductive substance on inner walls of micro holes provided in a substrate using a fluid obtained by dissolving a metal complex in a supercritical fluid. Particularly, an electroconductive substance formed in micro holes using the method of the invention can be used as through wires.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-199678 | Sep 2011 | JP | national |
| 2011-218300 | Sep 2011 | JP | national |
| 2011-218301 | Sep 2011 | JP | national |
| 2011-218302 | Sep 2011 | JP | national |
This application is a continuation application based on a PCT Patent Application No. PCT/JP2012/073343, filed Sep. 12, 2012, whose priority is claimed on Japanese Patent Application No. 2011-199678, filed Sep. 13, 2011, Japanese Patent Application No. 2011-218300, filed Sep. 30, 2011, Japanese Patent Application No. 2011-218301, filed Sep. 30, 2011, and Japanese Patent Application No. 2011-218302, filed Sep. 30, 2011, the contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2012/073343 | Sep 2012 | US |
| Child | 14206615 | US |
