The present disclosure relates to a deposition head for depositing an organic film, for example, in manufacturing an organic EL device, and relates to a deposition apparatus including the deposition head.
Recently, an organic EL device utilizing electroluminescence (EL) has been developed. Since the organic EL device consumes lower power compared with a cathode-ray tube or the like and is self-luminescent, there are some advantages such as a view angle wider than that of a liquid crystal display (LCD).
The most basic structure of this organic EL device includes an anode (positive electrode) layer, a light-emitting layer, and a cathode (negative electrode) layer stacked sequentially on a glass substrate to form a sandwiched shape. In order to transmit light from the light-emitting layer, a transparent electrode made of ITO (Indium Tin Oxide) is used for the anode layer on the glass substrate. Such organic EL device is generally manufactured by forming the light-emitting layer and the cathode layer in sequence on the glass substrate having thereon the ITO layer (anode layer) and by additionally forming a sealing film.
The organic EL device as described above is generally manufactured by a processing system including various film forming apparatuses or etching apparatuses configured to form a light emitting layer, a cathode layer, a sealing layer, and the like.
By way of example, as a general method of forming a light emitting layer, there has been known a method in which a material gas is supplied to a deposition head from a material gas supply source and the material gas is discharged from the deposition head toward a glass substrate so as to be deposited thereon.
Patent Document 1 describes a deposition head 20 including a single dispersion plate 41 having multiple through-holes 40 as depicted in
However, if an organic film is formed by using a deposition head including a dispersion plate depicted in FIG. 2, the amount of the material gas passing through through-holes of the dispersion plate may vary depending on a distance from a supply port through which the material gas is supplied into the deposition head. Further, since an equi-thermal property of the material gas is not considered, there is a problem that a temperature of the material gas is not uniformized and a film is not formed on a substrate in a sufficiently uniform manner.
A deposition head including branch flow lines therein as depicted in
Accordingly, the present disclosure provides a deposition head capable of discharging a material gas having a uniform flow rate and equi-thermal property from each component in a large-sized substrate as well as a conventional small-sized one and capable of forming a uniform thin film and also provides a deposition apparatus including the deposition head.
In accordance with an aspect of the present disclosure, there is provided a deposition head provided within a deposition apparatus for forming a thin film on a substrate and configured to discharge a material gas toward the substrate. The deposition head may include an outer casing, and an inner casing provided within the outer casing and into which the material gas is introduced. In the inner casing, an opening configured to discharge the material gas toward the substrate may be formed, and a heater configured to heat the material gas may be provided at an outer surface of the outer casing or in a space between the outer casing and the inner casing.
Further, the heater may be fixed to a plate member provided between the outer casing and the inner casing, and the heater may be provided along a periphery of a side surface of the outer casing or the inner casing. The heater may include a sheath heater or a cartridge heater, and a spacer member configured to bring an inner surface of the outer casing into partial contact with an outer surface of the inner casing may be provided on at least one of the outer casing and the inner casing. Moreover, a sealed space may be formed between the outer casing and the inner casing. The heater may be provided within the sealed space, and a volatile liquid may be provided in the sealed space.
Further, thermal conductivity of the outer casing may be equal to or higher than thermal conductivity of the inner casing. In this deposition head, since the thermal conductivity of the outer casing is high, heat from the heater is rapidly transferred throughout the whole outer casing, and the whole outer casing is uniformly heated. Further, heat is transferred from the outer casing to the inner casing via a spacer member that brings the inner surface of the outer casing into partial contact with the outer surface of the inner casing. As a result, the inner casing is heated. In this case, the spacer member that brings the inner surface of the outer casing into contact with the outer surface of the inner casing may be provided over the whole outer casing or the whole inner casing. Therefore, the heat may be transferred substantially uniformly to the whole inner casing, and the whole inner casing may be uniformly heated. Thus, the material gas introduced into the inner casing may be heated under the substantially same conditions and the material gas may have a uniform temperature within the inner casing. Thus, the material gas with the uniform temperature distribution may be discharged through the opening toward the substrate and a uniform film may be formed.
The spacer member may be provided on either or both of the outer casing and the inner casing, and a spacer member provided on the outer casing may be made of a material different from a material of a spacer member provided on the inner casing. The spacer member may include multiple protrusions formed by press molding or a filling material.
The press molding may include an emboss processing or a welding processing. A material of the outer casing may include stainless steel or copper. A material of the inner casing may include stainless steel. A thickness of at least a part of the inner casing may be about 3 mm or less. A gas dispersion plate may be provided within the inner casing. The gas dispersion plate may include a mesh-shaped baffle plate or a punching metal plate.
A thermal conductive film may be formed on either or both of the inner casing and the outer casing. The thermal conductive film may be formed on at least an outer surface of the inner casing. A discharge plate configured to uniformly discharge the material gas may be provided in the opening. The discharge plate may include a slit configured to discharge the material gas or the discharge plate may include multiple discharge holes configured to discharge the material gas. The discharge plate may be formed of a stainless steel plate, a stainless block, a cooper plate, or a copper block.
In accordance with another aspect of the present disclosure, there is provided a deposition apparatus for forming an organic thin film on a substrate. The deposition apparatus may include a processing chamber configured to accommodate therein a substrate; and a deposition head including an opening configured to discharge a material gas toward the substrate within the processing chamber. The deposition head may include a carrier gas supply unit configured to supply a carrier gas that transports the material gas. An inside of the processing chamber may be depressurized.
In accordance with the present disclosure, there is provided a deposition head capable of discharging a material gas at a uniform flow rate and temperature from each component toward a large-sized substrate as well as a conventional small-sized one while securing equi-thermal property and capable of forming a uniform thin film, and a deposition apparatus including the deposition head.
1: Film forming apparatus
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the specification and the drawings, elements having substantially the same function are assigned same reference numerals and redundant description thereof may be omitted.
The chamber 10 may include an exhaust port 14 through which exhaustion is performed by a vacuum pump 13. During a film formation, the insides of the chamber 10 and the substrate holding chamber 11 may be in a vacuum state. The deposition head 20 may communicate, via a material supply line 31, with a material supply unit 30 provided outside the chamber 10. Further, a valve 32 configured to control a supply of a material gas may be provided in the material gas supply line 31. The material supply line 31 may be connected to a gas retreat line 33 communicating with the vacuum pump 13 and retreating a gas when the valve 32 is closed. Further, a valve 34 may be provided in the gas retreat line 33. The deposition head 20 may be connected to a gas outlet line 35 communicating with the vacuum pump 13 and collecting a remaining material gas within the deposition head 20 after the film formation. Further, a valve 36 may be provided in the gas outlet line 35.
In the deposition head 20 provided within the film forming apparatus 1 configured as described above, in order to form a uniform thin film on the substrate G, it may be required to discharge the material gas supplied from the material supply unit 30 toward the substrate G through the opening 21 at a flow rate as uniform as possible and with a secured equi-thermal property.
Above all, as depicted in
Then, as depicted in
Subsequently, as depicted in
Thereafter, as depicted in
In the organic EL device A manufactured as described above, the light emitting layer 51 may emit light by applying a voltage between the anode layer 50 and the cathode layer 52. This organic EL device A can be used for a display device or a surface light emitting device (illumination/light source) and can be used for other electronic devices.
Then, the deposition apparatus 60 for forming the light emitting layer 51 depicted in
The deposition apparatus 60 may include a sealed processing chamber 61. The sealed processing chamber 61 may have a rectangular shape of which a longitudinal direction corresponds to a transfer direction of the substrate G. Front and rear surfaces of the processing chamber 61 may be connected to another film forming apparatus or the like via gate valves 62.
A bottom surface of the processing chamber 61 may be connected to an exhaust line 63 including a vacuum pump (not illustrated), so that the inside of the processing chamber 61 may be depressurized. Further, the processing chamber 61 may include therein a holding table 64 configured to horizontally hold the substrate G. The substrate G may be mounted on the holding table 64 in a face-up state in which the substrate G's upper surface on which the anode layer 50 is formed faces upwards. The holding table 64 may be configured to move on a rail 65 provided along the transfer direction of the substrate G so as to transfer the substrate G.
On a ceiling surface of the processing chamber 61, multiple deposition heads 66 (for example, six in
The first casing 70 and the second casing 71 may have a rectangular shape. The first casing 70 may be slightly larger than the second casing 71. Further, the deposition head 66 may be configured to include the first casing 70 inserting the second casing 71 therein. Openings 72 and 73 may be formed on a lower surface of the first casing 70 and a lower surface of the second casing 71, respectively. The second casing 71 may be inserted into the lower opening 72 of the first casing 70, so that both openings 72 and 73 may be overlapped with each other.
The first casing 70 may be made of a material having higher thermal conductivity than the second casing 71. For example, copper may used for the first casing 70. An upper surface (a surface facing the opening 72) of the first casing 70 may be connected to the material supply line 68 communicating with the material supply source 67 depicted in
Between side surfaces 75 and 76 of the first casing 70, the side surface 75 is larger than the side surface 76. The side surface 75 may include a groove 80 in which a heater 77 is embedded. The heater 77 may be provided along a periphery of the square-shaped side surface 75. Since the heater 77 is embedded in the groove 80, a contact surface between the side surface 75 of the first casing 70 and the heater 77 may increase, resulting in an increase of thermal conductivity.
In the drawing, the groove 80 may extend to a side surface of the material supply line 68 connected to the upper surface of the first casing 70, and the heater 77 may be embedded therein.
In order to embed the heater 77 in the groove 80, as depicted in
Between the side surfaces 75 and 76 of the first casing 70, the side surface 76 is smaller than the side surface 75. The side surface 76 may have thereon a heater block 81 including therein a heater 78. The heater block 81 may be made of a material having high thermal conductivity such as copper. A surface of the heater block 81 may be contacted with the side surface 76 of the first casing 70. Thus, heat transferred from the heater 78 to the heater block 81 may be rapidly transferred to the entire side surface 76 of the first casing 70.
The inner casing 71 may be made of a material having less thermal conductivity than the first casing 70. For example, stainless steel may be used for the inner casing 71. In an upper surface (a surface facing the opening 73) of the inner casing 71, a material gas inlet port 82 through which a material gas is introduced from the material supply line 68 may be formed.
As depicted in
As depicted in
Within the processing chamber 61 of the deposition apparatus 60 including the deposition head 66 depicted in
In the deposition head 66 depicted in
That is, in the deposition head 66 in accordance with the present embodiment, as depicted in
If the material gas is discharged to a large-sized substrate used for a large-sized display, which is recently in high demand, a metal plate structure formed by cutting steel may be provided. In this case, as compared with the conventional deposition head including therein branch flow lines, it may be possible to greatly reduce manufacturing costs for the deposition head 66 in accordance with the present embodiment. Conventionally, a sheet-shaped heater (mica heater) of high cost has been used for a deposition head that discharges a material gas onto a small-sized substrate for a small-sized display. However, if the sheet-shaped heater is used for a large-sized deposition head for a large-sized substrate costs may be increased due to the large size. Therefore, by using pipe-shaped heaters 77 and such as the sheath heater or the cartridge heater described in the present embodiment together with the sheet-shaped heater, it may be possible to reduce cost, and also possible to secure an equi-thermal property within the deposition head.
There has been described the embodiment of the present disclosure, but the present disclosure is not limited to the above-described embodiment. It would be understood by those skilled in the art that various changes and modifications may be made within the scope of the accompanying claims and it shall be understood that all changes and modifications are included in the scope of the present disclosure.
By way of example, in the above-described embodiment, the deposition apparatus 60 for manufacturing the organic EL device A has been explained. Further, the present disclosure can be also applied to a case where a film is formed by means of deposition such as Li deposition in processes of various electronic devices. Although it has been described that the substrate G as a target object is a glass substrate, the glass substrate may include a silicon substrate, a square substrate, a circular substrate or the like. Further, the present disclosure can be applied to a target object other than a substrate.
In the present embodiment, it has been described that the heaters 77 (groove 80) and 78 (heater block 81) are provided in both side surfaces 75 and 76 of the deposition head 66. However, the present disclosure is not limited thereto, and the heaters 77 and 78 may be provided in only one of the side surfaces 75 and 76. That is, one of the heaters 77 and 78 provided in the side surfaces 75 and 76 may be omitted. Desirably, a shape, the number, and an arrangement of the heaters 77 and 78 may be changed appropriately depending on a deposition head 66's temperature measured while being heated. The arrangement thereof is not limited to an example shown in
By way of example,
In the deposition head 66 in accordance with the above-described embodiment, as depicted in
If an equi-thermal property is sufficiently secured in the side surface 75, even if arrangement density of the heater 77 is reduced, the equi-thermal property within the deposition head 66 can be sufficiently secured. Therefore, as depicted in
The arrangement shape of the heater 77 depicted in
In the deposition head 66 in accordance with the above-described embodiment, the first casing 70 may be made of copper; the second casing 71 may be made of stainless steel; and the heater 77 may be provided in the outer surface of the first casing 70. However, the present disclosure is not limited thereto. The heater 77 does not need to be provided in the outer surface of the first casing 70 in order to secure the equi-thermal property within the deposition head 66. Therefore, hereinafter, there will be explained, as a second another embodiment of the present disclosure, an example where an arrangement of the heater 77 and a material of each casing are different from the above-described embodiment.
By way of example, in the second another embodiment of the present disclosure, the first casing 70 and the second casing 71 may be made of stainless steel, and only the second casing 71 may be coated with a thermal conductive film such as a copper coating having a thickness of about 30 microns or more. In this case, desirably, the heater 77 may be provided between the first casing 70 and the second casing 71 differently from the above-described embodiment. Further, in addition to the second casing 71, if required, the first casing 70 may be coated appropriately with the thermal conductive film in order to reduce non-uniformity in temperatures on a cross section within a deposition head 66. That is, whether either or both of the first casing 70 and the second casing 71 is coated with the thermal conductive film may be determined appropriately depending on temperature differences on the cross section within the deposition head 66. Further, it may be allowed to coat only one side of each casing with the thermal conductive film. However, typically, in case of a copper coating, for example, since a stainless steel plate is immersed in a copper coating tank, the copper coating may be generally performed on both sides of the stainless steel plate.
As described above, since each casing (particularly, the second casing 71) made of stainless steel is coated with a thermal conductive film such as a copper coating, it may be possible to secure hardness of the casing against thermal deformation. Further, thermal conductivity may be increased, and, thus, it may be possible to suppress non-uniformity in temperature in each component within the deposition head 66. Since thermal conductivity of each casing (particularly, the second casing 71) is increased, the number of the heaters 77 can be reduced as depicted in
That is, since the first casing 70 and the second casing 71 are made of stainless steel, costs can be greatly reduced, and hardness can be increased as compared with a case where a casing is made of copper. Further, since the stainless steel may be coated with the thermal conductive film, an equi-thermal property within the deposition head 66 can be secured. Further, it may be possible to avoid deformation caused by the copper heat, which may be generated in a case where a casing is made of a copper plate having high thermal conductivity. Herein, the copper coating has been described as the thermal conductive film for increasing thermal conductivity of the stainless steel. However, the thermal conductive film may not be limited to the copper coating. Instead, a film having a higher thermal conductivity than a basic material (material of a casing) can be employed. By way of example, it may be possible to conduct a coating capable of increasing thermal conductivity such as a gold coating and a silver coating. Further, a thermal conductive film may be formed by a junction process of the foil such as a gold/silver foil, or a blast process or a diffusion junction process. However, it may be desirable to conduct a copper coating in view of costs.
In the deposition head 66 in accordance with the above-described embodiment, the opening 72 (73) may be formed by opening one of the side surfaces of the rectangular casing. The material gas within the deposition head 66 may be dispersed by the gas dispersion plate (baffle plate 83) provided in the deposition head 66 and discharged to the substrate G through the opening 72 (73). However, the material gas within the deposition head 66 cannot be dispersed sufficiently by only the gas dispersion plate. Therefore, the material gas may not be discharged uniformly to the substrate G through the opening 72 (73), and a film may not be formed uniformly. In this case, desirably, an discharge plate formed of, for example, a copper plate and configured to allow the material gas to be discharged uniformly through the opening 72 (73) may be provide in the deposition head 66 described in the above-described embodiment.
In the above-described embodiment, as depicted in
Hereinafter, as a third another embodiment of the present disclosure, there will be explained a deposition head 66 having the sealed space 100, with reference to the accompanying drawings.
As depicted in
The inside of the sealed space 100 may be in a sealed state, and the liquid L and the heater 77 may be provided therein. The amount of the liquid L may not be sufficient enough to fill the entire inside of the sealed space 100, but may be sufficient to exist at a bottom portion of the sealed space 100. In the present embodiment, the heater 77 may be immersed in the liquid L existing within the sealed space 100. Further, the heater 77 may have a sufficient size/length to heat the liquid L existing at a bottom portion of the sealed space 100. The size/length thereof can be determined appropriately.
In the sealed space 100, the liquid L existing within the sealed space 100 may be evaporated by being heated by the heater 77. Evaporated steam may contact with the entire inner surface of the sealed space 100, so that the sealed space 100 can be heated over all. That is, the sealed space 100 may have a configuration/operation similar to a so-called “heat pipe”. In this case, the liquid L's steam may be cooled by means of heat exchange with the inner surface after contacting with the inner surface of the sealed space 100, and liquefied (liquid L) so as to exist within the sealed space 100. That is, the liquid L may circulate within the sealed space 100 while repeating evaporation and liquefaction. Further, in the present embodiment, a shape of the inner surface of the sealed space 100 is not limited, and may be a typical plane. However, in order to reflux the liquefied liquid L upon contacting with the inner surface of the sealed space 100, into the liquid L existing at the bottom portion of the sealed space 100 with more efficiency, desirably, the inner surface of the sealed space 100 may have a large surface area and a shape which may easily cause a capillary phenomenon. By way of example, the surface process may be performed on the inner surface of the sealed space 100 to have a mesh shape or a groove shape.
In the above-described deposition head 66 around which the sealed space 100 is formed, when a material gas is supplied, the liquid L within the sealed space 100 may be heated by the heater 77 so as to be vaporized. Therefore, the sealed space 100 may be filled with the vapor having an approximately constant temperature. Thus, the deposition head 66's side surface entirely covered by the sealed spaces 100 may be uniformly heated by the respective sealed spaces at a certain temperature. Therefore, the material gas supplied from the material supply line 68 may be uniformly heated within the deposition head 66 at a certain temperature. Since the sealed spaces 100 are provided in the entire side surface of the deposition head 66, the side surface can be uniformly heated with high accuracy. Further, the material gas within the deposition head 66 can be uniformly heated by radiant heat with high accuracy from the uniformly thermalized side surfaces of the deposition head 66.
Since a temperature of the heater 77 provided in each sealed space 100 can be controlled, an internal temperature of each sealed space 100 can be controlled. The internal temperature of each sealed space 100 can be controlled appropriately based on a measured temperature distribution within the deposition head 66, and the deposition head 66 can be uniformly heated to become a certain temperature with high accuracy. That is, even if a part of the deposition head 66 may have a temperature lower than other portions thereof, by appropriately controlling a temperature of each sealed space 100 corresponding to the low-temperature portion, the whole inside of the deposition head 66 can be quickly and uniformly heated.
It has been explained that in the present embodiment (third another embodiment), the side surface 75 of the deposition head 66 may be divided into three portions in a longitudinal direction, and the three sealed spaces 100 respectively corresponding thereto may be formed. The present disclosure is not limited to this embodiment. The number or positions of the sealed spaces 100 formed in the side surface of the deposition head 66 can be appropriately changed so as to efficiently and uniformly heat the inside of the deposition head 66.
In the above-described embodiment, the deposition head 66 may include the first casing 70 and the second casing 71. The deposition head 66 of the present disclosure is not limited thereto. In the present disclosure, the deposition head 66 need not have a casing. By way of example, a plate-shaped member in a casing shape may be provided.
In the above-described embodiment, the multiple protrusions 85 serving as the spacer members configured to bring the inner surface of the first casing 70 into partial contact with the outer surface of the second casing 71 may be formed in the entire outer surface of the second casing 71. However, the present disclosure is not limited thereto. The protrusions 85 may be formed on the inner surface of the first casing 70, or the protrusions 85 may be formed on the inner surface of the first casing 70 and the outer surface of the second casing 71. Here, the material of the protrusions 85 formed on the inner surface of the first casing 70 is different from that on the outer surface of the second casing 71. Further, as the spacer member, a filling material such as steel wool may be used.
As an experimental example 1 of the present disclosure, a deposition head having a configuration depicted in
A temperature difference between a central portion of an outer wall and a periphery portion of the outer wall in
As an experimental example 2 of the present disclosure, there is measured a temperature distribution on a cross section within a deposition head while varying an arrangement of a heater and changing presence/absence of a copper coating as a thermal conductive film.
As depicted in
It can be seen from the result of the experimental example 2 that when the heater density is suppressed to be low and the surface having the heater is covered with the cooper coating (thermal conductive film), the temperature difference on the cross section within the deposition head can be reduced and a sufficient equi-thermal property can be secured. That is, by forming the thermal conductive film on the surface having the heater, the number of heaters can be reduced and the equi-thermal property can be secured, resulting in a cost reduction.
The present disclosure can be applied to, for example, a deposition head used for depositing an organic film in manufacturing an organic EL device and a deposition apparatus including the deposition head.
Number | Date | Country | Kind |
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2009-090846 | Apr 2009 | JP | national |
2009-164935 | Jul 2009 | JP | national |
2010-041352 | Feb 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2010/056064 | 4/2/2010 | WO | 00 | 10/26/2011 |