JP2004149857A - Cat-PECVD DEVICE, AND FILM TREATMENT SYSTEM USING THE SAME - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remarkably reduce device cost by the simplification of maintenance operation for the device, the reduction of the time therefor, and the realization of the continuous operation of depositing different kinds of electrically conductive films in the same film deposition chamber. <P>SOLUTION: In the Cat-PECVD (Catalytic Plasma Enhanced Chemical Vapor Deposition) device, separately from a heat catalytic body arranged at a non-Si non-C based gas introduction passage, a second heat catalytic body is arranged at the film deposition space; a gas for cleaning comprising at least any selected from gaseous hydrogen, a gas comprising fluorine (F) in molecular formula and a gas comprising chlorine (C) in molecular formula is introduced at least through the non-Si non-C based gas introduction passage into the film deposition space and is heated and activated by the first heat catalytic body and the second heat catalytic body; and depositions deposited inside the film deposition chamber composing the film deposition space are removed by etching with the activated gas. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a PECVD (Plasma Enhanced Chemical Vapor Deposition) method, which is a CVD (Chemical Vapor Deposition) method using plasma as a means for decomposing and activating a film forming gas, and a method for decomposing and heating a film forming gas. A new CVD that combines a Cat-CVD (Catalytical Chemical Vapor Deposition) method (HW-CVD (Hot-wire CVD) method which is the same principle) as a CVD method using a thermal catalyst as an activating means. And a film processing system using the same.
[0002]
[Prior art and its problems]
In thin film deposition using a vacuum apparatus, it is usually difficult to limit the thin film deposition to only the desired substrate, and the film or powder adheres to the deposition chamber other than the desired substrate inevitably. I do. These deposits act as contamination sources in various ways, such as a source of impurities and a source of foreign substances, with respect to film formation on a desired substrate. Periodic removal (cleaning) is essential.
[0003]
In the cleaning method usually performed, the apparatus is opened to the atmosphere, and the inner wall and internal components of the film forming chamber are cleaned using a mechanical means such as wiping or scraping or a chemical solution such as an etching solution. However, this method requires a very long time for evacuation after cleaning in order to release the apparatus to the atmosphere, and requires much time and labor for cleaning itself, which causes a problem that the productivity of the apparatus is significantly reduced. In particular, in the case of a product having a very large production amount, such as a thin film Si-based solar cell, and therefore a thin film forming apparatus in which thin film formation is performed in a large amount in a short time, the method has a fatal decrease in productivity, that is, a drastic decrease in productivity. Cost increase.
[0004]
On the other hand, there is known a method (in-situ cleaning) in which cleaning of the inside of the apparatus is performed simply and in a short time while maintaining a vacuum state by flowing a cleaning gas without opening the apparatus to the atmosphere. A typical method is to decompose and activate a gas containing fluorine (F) or chlorine (Cl) as a cleaning gas by plasma, and to react the activated gas with the deposit to vaporize and exhaust. That is. However, usually, plasma cannot be generated in the entire region of the apparatus, and the plasma generation region is limited to a part of the apparatus. Therefore, there is a problem that the removal of the deposit is insufficient.
[0005]
In contrast, ClF ₃ Also known is an in-situ cleaning method of raising the temperature of a film forming chamber to a predetermined temperature using a highly reactive gas such as the above, and reacting and vaporizing the reactive gas and attached matter to remove the exhaust gas. Have been. This compensates for the drawbacks of the method using plasma as long as the temperature of the entire region of the film forming chamber can be raised to a predetermined temperature, but usually the temperature in the film forming chamber needs to be about 200 ° C. Therefore, there is a problem that a considerable thermal load is applied to the apparatus, and a considerable time is required for a temperature rising process before cleaning and a temperature decreasing process after cleaning (see Patent Document 1).
[0006]
In view of the above, an in-situ cleaning method using a thermal catalyst has been proposed (see Patent Literature 1 and Patent Literature 2). In this method, the cleaning gas is heated and activated by a thermal catalyst (heating element) made of a metal, and the activated gas and the deposit are reacted and vaporized to remove the exhaust gas. FIG. 11 shows a schematic diagram of an apparatus for realizing the present method. Reference numeral 600 denotes a shower head for ejecting a cleaning gas, 601 denotes a cleaning gas inlet, 602 denotes a cleaning gas outlet, 603 denotes an active gas space in which the cleaning gas is activated, and 604 denotes heating and activation of the cleaning gas. 605 is a heating power supply for heating the thermal catalyst, and 608 is a vacuum pump for exhausting gas. Although not a component of the present method, FIG. 11 also shows a substrate (606) and a substrate heater (607), which are components when the present apparatus is used as a film forming apparatus.
[0007]
By the way, the present inventors have been studying a new CVD method in which the PECVD method and the Cat-CVD method are integrated, and have already referred to a method named Cat-PECVD method in Patent Documents 3 to 6 and the like. Has been disclosed. FIG. 5 is a schematic view of an apparatus for realizing a parallel plate electrode type Cat-PECVD method, and FIGS. 6 to 10 are schematic views of an apparatus for realizing an antenna electrode type Cat-PECVD method.
[0008]
Here, in FIG. 5, 700 is a showerhead, 701 is a raw material gas inlet containing a gas containing Si and / or C in a molecular formula, and 702 is a non-Si non-gas made of a gas not containing Si and C in a molecular formula. C-based gas introduction port, 703 is a raw material gas introduction path, 704 is a non-Si non-C-based gas introduction path, 705 is a thermal catalyst, 706 is a heating power supply, 707 is a plasma space, 708 is a plasma generation electrode, 709 Is a high frequency power supply, 710 is a source gas outlet, 711 is a non-Si / non-C gas outlet, 712 is a substrate for film formation, 713 is a heater for heating the substrate, 714 is a vacuum pump for gas exhaust, and 715 is a gas pump. It is a radiation blocking member.
[0009]
FIG. 6 is an overall view showing an example of an apparatus for realizing the antenna electrode type Cat-PECVD method. In the case where the film-forming surface of the flat substrate is oriented in the direction perpendicular to the paper, the thermal catalyst is built in. FIG. 5 is a cross-sectional view at the position of the antenna electrode. FIG. 7 shows an example in which tubular antenna electrodes are arranged in an array, and is a cross-sectional view in the case where the film-forming surface of the substrate is oriented in a direction parallel to the paper surface. Only a part of the antenna electrode unit is shown, and details of the end structure of the antenna electrode are omitted: refer to FIGS. FIG. 8 is a sectional view showing a detailed structure of an antenna electrode having a built-in thermal catalyst. FIG. 9 is a perspective view showing a three-dimensional structure of an antenna electrode incorporating a thermal catalyst. FIG. 10 is a cross-sectional view of an antenna electrode having a double tube structure and incorporating a thermal catalyst.
[0010]
6 to 10, reference numeral 101 denotes an inlet for a non-Si non-C-based gas composed of a gas not containing Si and C in a molecular formula, and 102 denotes a raw material gas containing a gas containing Si and / or C in a molecular formula. , 103 is a thermal catalyst, 104 is a power supply for heating the thermal catalyst 103, 105 is an active gas space, 106a is an antenna electrode containing a thermal catalyst, 106b is an antenna electrode not containing a thermal catalyst, 107a And 107b are high-frequency power supplies, 108a and 108c are phase converters, 108b and 108d are power distributors, 109 is a base for film formation, 110 is a heater for heating the base, and 111a is provided on the antenna electrode 106a with a built-in thermal catalyst. Gas outlet (the same gas outlet is provided on the antenna electrode without a built-in thermal catalyst, but the description is omitted). Wood, 113 chambers constituting the film space (film deposition chamber), 114a and 114b, the hollow portion provided in the antenna electrode, 201 is a gas discharge port. The gas outlet is connected to a vacuum pump, but is not shown.
[0011]
Hereinafter, the Cat-PECVD method will be described based on a parallel plate electrode type Cat-PECVD apparatus shown in FIG. 5, but the same principle will be described with reference to an antenna electrode type Cat-PECVD apparatus shown in FIGS. Needless to say, the same applies to a PECVD apparatus.
[0012]
The Cat-PECVD method uses, for example, SiH ₄ With H as a non-Si non-C-based gas ₂ , Each of which is separated and introduced into the film forming chamber through a different gas introduction path. ₂ Is heated and activated by the thermal catalyst 705 installed in the gas introduction path, ₄ Is to form a Si-based film by being mixed in the plasma space 707, and a high-quality crystalline Si film having high crystallinity can be easily obtained even under high-speed film forming conditions. Also, a high-quality hydrogenated amorphous silicon film having a low hydrogen concentration and a small degree of light degradation can be obtained even under high-speed film formation conditions. This is because the use of a thermal catalyst in this method ₂ The amount of heating and activation of ₄ Can be freely controlled independently of the amount of decomposition and activation of ₄ Is activated only by plasma, so that undesired radical generation by the thermal catalyst 705 can be avoided, and a radiation blocking member 715 can be provided, so that radiation that directly reaches the base 712 from the thermal catalyst 705 can be prevented. It can be shut off to avoid an undesired rise in the film forming surface temperature, and furthermore, the gas heating effect of the thermal catalyst 705 suppresses the higher order silane generation reaction in the gas phase (SiH ₂ Since the higher silane generation reaction due to the molecule insertion reaction is an exothermic reaction, an increase in gas temperature due to gas heating has an effect of applying a brake to the higher silane generation reaction).
[0013]
The advantage of the antenna electrode type over the parallel plate type electrode is that a large-area uniform film can be easily formed even by using VHF plasma.
[0014]
Now, the in-situ cleaning method using a thermal catalyst disclosed in Patent Document 1 and Patent Document 2 described above is too large to be applied to the Cat-PECVD method developed by the present inventors. It turned out that there was a problem.
[0015]
That is, in the Cat-PECVD method, a thermal catalyst is provided in the introduction path of the non-Si non-C-based gas among the separated and introduced gases, and ideally, Si or Deposits such as films and powders containing C should not be generated. However, in practice, for example, as described above, SiH ₄ When using as the source gas, the SiH ₄ Or the SiH ₄ Gas molecules containing Si generated by various reactions in the plasma space using as a base gas slightly diffuse into and enter the non-Si non-C-based gas introduction path, and are heated / heated by the thermal catalyst disposed in the gas introduction path. By the activation, the generation of the deposits may occur to some extent in the gas introduction pipe. However, in the in-situ cleaning method using the thermal catalyst, the thermal catalyst is Since it is arranged only in the film-forming space downstream of the shower head (accordingly, the gas introduction path), the deposits generated in the non-Si non-C-based gas introduction path cannot be easily removed.
[0016]
Further, it is apparent that this does not easily allow the film forming chamber to be used in such a manner that a film of a different conductivity type is continuously formed. That is, before forming the target film, the conductivity type determining element (doping element) of the deposit already generated on the inner surface of the film forming chamber or the inner surface of the gas introduction path according to the film forming history up to that time is the target. This is because the determination of the conductivity type of the film and the degree of doping thereof, that is, the film quality are affected.
[0017]
In view of the above, the present inventors have disclosed a method for removing deposits generated in the gas introduction path in Patent Document 7. That is, H is used as the cleaning gas. ₂ Then, the gas is heated and activated by a thermal catalyst to remove deposits in the gas introduction path. At this time, regarding the cleaning of the inner wall of the film forming chamber on the film forming space side, the gas activated by the thermal catalyst is further activated by plasma in the film forming space. Cleaning was more effective than in the case.
[0018]
However, in Patent Document 7, the means for activating the gas existing on the film forming space side is limited to plasma. For this reason, the above-described problem in the case of using the plasma (the difficulty in cleaning the entire film forming space because the plasma generation position is limited to a predetermined position) has not been solved yet.
[0019]
The present invention has been made under such a background, and an object of the present invention is to provide a Cat-PECVD apparatus that realizes an excellent and effective gas cleaning method and a film processing system that realizes the Cat-PECVD apparatus. In particular, in the formation of a Si-based thin film in a photoelectric conversion device represented by a thin-film Si-based solar cell, etc., simplification and time reduction of device maintenance work, and continuous formation of different conductivity type films in the same deposition chamber. An object of the present invention is to significantly reduce the cost of the apparatus by making it possible.
[0020]
[Patent Document 1]
JP 2001-49436 A
[Patent Document 2]
JP-A-2001-49437
[Patent Document 3]
Japanese Patent Application No. 2000-130858
[Patent Document 4]
Japanese Patent Application No. 2001-293031
[Patent Document 5]
Japanese Patent Application No. 2002-67445
[Patent Document 6]
Japanese Patent Application No. 2002-155537
[Patent Document 7]
Japanese Patent Application No. 2002-007147
[0021]
[Means for Solving the Problems]
The Cat-PECVD apparatus of the present invention includes a raw material gas containing a gas containing Si and / or C in a molecular formula, and a Si and C gas in a molecular formula heated by a first thermal catalyst disposed in a gas introduction path. A non-Si non-C-based gas composed of a gas containing no gas is separated from a plurality of gas ejection ports provided in a shower head serving also as a plasma generation electrode installed in the film formation space, in a state where the gases are separated from each other. The gas ejected to the film forming space and mixed therewith is decomposed and activated by plasma generated by the shower head connected to a high-frequency power supply, and faces the shower head in the film forming space. A Cat-PECVD apparatus in which a film is deposited on a substrate arranged in a second direction, wherein the second catalyst is different from the thermal catalyst disposed in the non-Si non-C-based gas introduction path. A catalyst is disposed in the film-forming space, and is used for cleaning containing at least one of hydrogen gas, a gas containing fluorine (F) in a molecular formula, or a gas containing chlorine (Cl) in a molecular formula. A gas is introduced into the film formation space through at least the non-Si non-C-based gas introduction path, and is heated and activated by the first thermal catalyst and the second thermal catalyst, and is heated and activated. A cleaning mechanism is provided for etching and removing deposits deposited in the film forming chamber constituting the film forming space by gas.
[0022]
In addition, a raw material gas containing a gas containing Si and / or C in a molecular formula, and a gas containing no Si and C in a molecular formula heated by a first thermal catalyst disposed in a gas introduction path. The Si non-C-based gas is separated from the Si non-C-based gas through a plurality of gas outlets provided in the antenna electrode through a hollow portion of an antenna electrode having a hollow structure installed in a film forming space. The gas spouted into the film space, mixed and spouted into the film formation space is decomposed and activated by the plasma generated by the antenna electrode connected to a high-frequency power supply, and is applied to the antenna electrode in the film formation space. A Cat-PECVD apparatus in which a film is deposited on a substrate disposed opposite to the substrate, wherein the second thermal element is different from the thermal catalyst disposed in the non-Si non-C-based gas introduction path. Catalyst body in front The cleaning gas, which is disposed in the film forming space and contains at least one of hydrogen gas, gas containing fluorine (F) in molecular formula, or gas containing chlorine (Cl) in molecular formula, contains at least It is introduced into the film forming space through the non-Si non-C-based gas introduction path, heated and activated by the first thermal catalyst and the second thermal catalyst, and is heated and activated by the heated and activated gas. A cleaning mechanism for etching and removing deposits deposited in the film forming chamber forming the film space is provided.
[0023]
In each of the above Cat-PECVD apparatuses, the gas containing fluorine (F) in the molecular formula or the gas containing chlorine (Cl) in the molecular formula is SF ₆ , NF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , CCl ₄ , C ₂ ClF ₅ , ClF ₃ , CCIF ₃ , And at least one of them.
[0024]
The film processing system according to the present invention is a film processing system including a plurality of vacuum chambers including at least one film forming chamber including the above-described Cat-PECVD apparatus, wherein the film forming chamber includes a Si-based film or a C-based film. It is characterized by having a structure in which at least one of a doping gas capable of forming a p-type and a doping gas capable of forming an n-type can be introduced.
[0025]
Further, in the above-described film processing system, a Si-based film or a C-based film in which at least two or more films having different conductivity types are stacked among a p-type film, a substantially i-type film, and an n-type film is manufactured. In forming the film, at least immediately before forming the i-type film, the film forming chamber is cleaned with a cleaning gas.
[0026]
Further, the film processing system is characterized in that a shelter which is separated by a vacuum valve and can store a substrate is provided adjacently.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings schematically illustrating the embodiments.
[0028]
FIG. 1 is an overall view showing an example of an apparatus for realizing a parallel plate electrode type Cat-PECVD method. Here, 705a is a first thermal catalyst disposed in a non-Si non-C-based gas introduction path, 705b is a second thermal catalyst disposed in a film forming space, and 706a is a first thermal catalyst. 706b is a heating power supply for the second thermal catalyst, and the other numbers are the same as those in FIG.
[0029]
FIG. 2 is an overall view showing an example of an apparatus for realizing the Cat-PECVD method of the antenna electrode type. In the case where the film-forming surface of the flat substrate is oriented in the direction perpendicular to the paper, the thermal catalyst is It is sectional drawing in the position of the built-in antenna electrode. FIG. 3 is a cross-sectional view of the array-like antenna electrode as viewed from the center axis direction.
[0030]
In these figures, 103a is a first thermal catalyst disposed in a non-Si non-C-based gas introduction path, 103b is a second thermal catalyst disposed in a film forming space, and 104a is a first thermal catalyst. A heating power supply for the catalyst body, 104b is a heating power supply for the second thermal catalyst body, 109a and 109b are bases, 111b is a gas outlet provided in the non-thermal catalyst body built-in antenna electrode 106b, Are the same as those in FIG.
[0031]
In the following, description will be made mainly on the parallel plate type Cat-PECVD apparatus shown in FIG. 1 as an example, but the same description will be applied to the antenna electrode type Cat-PECVD apparatus shown in FIG. 2 and FIG. Since the present invention can be applied, the description is omitted except for the parts that require individual description.
[0032]
Now, for example, using the Cat-PECVD apparatus shown in FIG. ₄ And H as a non-Si non-C gas ₂ The following describes an example in which a Si-based film is formed on a substrate by using the above method.
[0033]
When a Si-based film is formed on a substrate, a Si-based film or powder adheres inevitably to a film forming chamber other than the substrate. Further, in the Cat-PECVD method, the first thermal catalyst 705a is in a heating state in the film forming mode, and therefore, depending on the film forming conditions, as described in the section of the prior art and the problem thereof, the non-Si non-Si The deposit may also be generated near the thermal catalyst in the C-based gas introduction path.
[0034]
These deposits greatly affect the quality of the Si-based film formed on the substrate. That is, the dust quality caused by the delamination of the film as the deposit, the desorption of the powder, and the high-order silane-based gas generated by the reaction of the deposit with the active gas are taken into the Si-based film. Drops.
[0035]
Therefore, these deposits are removed at least once after the film forming mode and thereafter in the gas cleaning mode, and the presence of the deposits adversely affects the quality of a desired film formed on the substrate. Reduce the degree. The cleaning gas for gas cleaning is introduced from at least a non-Si non-C-based gas introduction path, and is heated and activated by the first thermal catalyst 705a and the second thermal catalyst 705b. The activated cleaning gas reacts with the deposit on the non-Si non-C-based gas introduction path and the deposit in the film forming space, and the deposit is vaporized and exhausted, and the cleaning proceeds.
[0036]
Here, as the cleaning gas, hydrogen (H ₂ ), A gas containing fluorine (F) in the molecular formula, or a gas containing chlorine (Cl) in the molecular formula. Examples of the gas containing fluorine in the molecular formula and the gas containing chlorine in the molecular formula include SF ₆ , NF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , CCl ₄ , C ₂ ClF ₅ , ClF ₃ , CCIF ₃ , Etc. can be used.
[0037]
Here, at least the surface of the thermal catalysts 705a and 705b is made of a metal material in order to make it function as a thermal catalyst by applying an electric current thereto and heating and raising the temperature by the Joule heat. More preferably, it is desirably made of a metal material containing at least one of Ta, W, Re, Os, Ir, Nb, Mo, Ru, and Pt which is a high melting point metal material as a main component. In addition, as the shape of the thermal catalyst, usually, the above-mentioned metal material is often used in the form of a wire. However, the shape is not particularly limited to the wire, and a plate-like or mesh-like one may be used. Can be. If the metal material as the thermal catalyst material contains impurities that are not preferable for film formation, before using the thermal catalysts 705a and 705b for film formation, the heating temperature must be higher than the heating temperature at the time of film formation. Preheating at a temperature for several minutes or more is effective in reducing impurities.
[0038]
In addition, as the heating power supplies 706a and 706b for the thermal catalysts 705a and 705b, it is usually convenient to use a DC power supply, but there is no problem even if an AC power supply with a low frequency that does not generate plasma is used.
[0039]
In addition, the temperature of the thermal catalyst varies depending on the type of cleaning gas used. For example, H ₂ The temperature is set to 1000 ° C. or higher for a cleaning gas that does not etch the thermal catalyst as in the above. H depending on pressure ₂ This is because the decomposition reaction of hydrogen into atomic hydrogen H becomes remarkable from about 1000 ° C. or higher, and the cleaning effect increases in accordance with the degree of decomposition. On the other hand, when a gas containing F or a gas containing Cl is used as a cleaning gas, if the temperature of the thermal catalyst is not sufficiently high, the thermal catalyst itself is consumed by etching due to a reaction with the cleaning gas. May be lost. In this case, the temperature of the thermal catalyst is increased to a temperature at which the cleaning gas or its decomposition component thermally desorbs from the surface of the thermal catalyst before the reaction between the thermal catalyst material and the cleaning gas proceeds. Just do it. Note that the temperature of the thermal catalyst must be lower than or equal to a level at which evaporation of the thermal catalyst material does not matter. The maximum use temperature varies depending on the material of the thermal catalyst, but a temperature approximately 500 to 1000 ° C. lower than the melting point of the material can be used as a rough guide.
[0040]
Here, the second thermal catalyst 705b disposed in the film-forming space is used for gas cleaning while the apparatus is used in a film-forming mode (the second thermal catalyst is not heated at this time). It is desirable to be able to arrange at a position different from the arrangement position in the film formation space in the mode. This is because, in the film formation mode, the second thermal catalyst becomes an object to which the above-mentioned deposits are adhered, causing the problems described above. Specifically, in FIG. 1, before the apparatus enters the film forming mode, the second thermal catalyst 705b is moved downward in advance and embedded in a groove (not shown) provided in the heater component. Evacuate. By doing so, the film can be formed under the same conditions as when the second thermal catalyst 705b does not exist, and the above problem can be avoided. It should be noted that the second method for retracting the thermal catalyst is not limited to the above-described method, and it is needless to say that the second thermal catalyst may be retracted in the horizontal direction.
[0041]
FIGS. 2 and 3 show an example of a method for disposing the second thermal catalyst 103b in the antenna electrode type Cat-PECVD method. In this case, the illustrated gas cleaning is also performed in the film forming mode. It is desirable to be able to arrange at a position different from the arrangement position in the mode for the same reason as above.
<Film processing system and process capable of forming different conductivity type semiconductor films in the same film forming chamber> FIG. 12 shows a pin type cell (FIG. 12) using an i-type hydrogenated amorphous silicon film as a photoactive layer. An example of a conventional apparatus for manufacturing a tandem thin-film Si solar cell in which a top cell) and a pin-type cell (bottom cell) using an i-type microcrystalline silicon film as a photoactive layer are shown. It is. Here, an example is shown in which the Cat-PECVD method is used to form the i-type hydrogenated amorphous silicon film and the i-type microcrystalline silicon film, but of course, other films (p-type film, n-type film) The Cat-PECVD method may be used for the formation.
[0042]
Here, FIG. 4 shows an example of an apparatus configuration when the gas cleaning method of the present invention is applied. Here, an example is shown in which the pin top cell is realized by one film forming chamber and the pin bottom cell is realized by one film forming chamber. A p-type doping gas typified by B2H6 and an n-type doping gas typified by PH3 are introduced into each of the film forming chambers so that a p-type film and an n-type film can be formed. As described above, the p-type film, the i-type film, and the n-type film are conventionally formed in independent film forming chambers as shown in FIG. For example, it is possible to remove deposits deposited in the deposition chamber up to that time by gas cleaning (that is, to erase the deposition history up to that point), so that films of different conductivity types can be continuously produced even in the same deposition chamber. The film can be made.
[0043]
In addition, when at least an i-type film is formed, gas cleaning is performed immediately before the film formation. This is because the quality of the i-type film determines the characteristics of the solar cell. On the other hand, in the case of forming a p-type film and an n-type film, it is not always necessary to perform gas cleaning immediately before the film formation. This is because the doping concentration of the p-type film and the n-type film for a solar cell is usually not so low as to be affected by the film forming history in the film forming chamber, but is often sufficiently high. However, it is needless to say that it is desirable to implement it.
[0044]
Although the continuous formation of the different conductivity type film by the gas cleaning method itself is a conventionally known technique, when the film forming method using the Cat-PECVD method is used, the gas cleaning method (the manufacturing method) of the present invention is used. It is apparent that a method of performing gas cleaning not only on the film chamber but also on the non-Si non-C-based gas introduction path) is essential.
[0045]
FIG. 4 also shows an evacuation chamber for temporarily evacuating the substrate during gas cleaning of the film forming chamber. Thereby, the influence of gas cleaning can be prevented from affecting the substrate.
[0046]
Further, in the above description, the case where three types of films of p-type, i-type, and n-type are formed in one film forming chamber has been described, but of course, two types of these films or one type of film are formed. It is needless to say that the present method can be applied to the case of forming a film.
[0047]
【The invention's effect】
As described above, according to the Cat-PECVD apparatus of the present invention and the film processing system using the same, it is possible to provide an excellent and effective gas cleaning method and an apparatus configuration for realizing the same. Significant time reduction can be realized.
[0048]
Further, since it becomes possible to continuously form films of different conductivity types in the same film forming chamber, the cost of the apparatus can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically illustrating an example of an apparatus for realizing a gas cleaning method according to the present invention.
FIG. 2 is a cross-sectional view schematically illustrating an example of an apparatus for realizing a gas cleaning method according to the present invention.
FIG. 3 is a diagram schematically illustrating an example of a device configuration for realizing a gas cleaning method according to the present invention, and is a cross-sectional view as viewed from a center axis direction of an antenna electrode.
FIG. 4 is a diagram illustrating an example of a film processing system that realizes the Cat-PECVD method according to the present invention.
FIG. 5 is a diagram schematically illustrating an example of a conventional Cat-PECVD apparatus.
FIG. 6 is a diagram schematically illustrating an example of a conventional Cat-PECVD apparatus.
FIG. 7 is a diagram schematically illustrating an example of the configuration of a conventional Cat-PECVD apparatus.
FIG. 8 is a cross-sectional view schematically illustrating an example of components of a conventional Cat-PECVD apparatus.
FIG. 9 is a perspective view schematically illustrating an example of components of a conventional Cat-PECVD apparatus.
FIG. 10 is a cross-sectional view schematically illustrating an example of components of a conventional Cat-PECVD apparatus.
FIG. 11 is a cross-sectional view schematically illustrating an example of an apparatus for realizing a conventional gas cleaning method.
FIG. 12 is a schematic diagram illustrating an example of a conventional film processing system.
[Explanation of symbols]
103a: the first thermal catalyst disposed in the non-Si non-C-based gas introduction path
101: inlet for non-Si non-C-based gas composed of a gas not containing Si and C in the molecular formula
102: Inlet of raw material gas containing gas containing Si and / or C in molecular formula 103: Thermal catalyst
103b: second thermal catalyst disposed in the film forming space
104: power supply for heating the thermal catalyst 103
104a: heating power supply for the first thermal catalyst
104b: heating power supply for the second thermal catalyst
105: Active gas space
106a: Antenna electrode with built-in thermal catalyst
106b: Antenna electrode without built-in thermal catalyst
107a, 107b: high frequency power supply
108a, 108c: phase converter
108b, 108d: power distributor
109: Substrate for film formation
109a, 109b: substrate
110: heater for heating the substrate
111b: antenna electrode without built-in thermal catalyst
111a: gas ejection port provided on the antenna electrode 106a with a built-in thermal catalyst
112: insulating member for electrical insulation
113: Chamber (film-forming room) constituting film-forming space
114a, 114b: hollow portions provided inside the antenna electrode
201: Gas outlet
700: shower head
701: Source gas inlet containing a gas containing Si and / or C in the molecular formula
702: Non-Si non-C based gas inlet made of a gas not containing Si and C in the molecular formula
703: Source gas introduction route
704: Non-Si non-C gas introduction route
705: thermal catalyst
705a: The first thermal catalyst disposed in the non-Si non-C-based gas introduction path
705b: second thermal catalyst disposed in the film forming space
706: Power supply for heating
706a: heating power supply for the first thermal catalyst
706b: heating power supply for the second thermal catalyst
707: Plasma space
708: electrode for plasma generation
709: High frequency power supply
710: Gas outlet for raw material gas
711 Non-Si / Non-C gas outlet
712: Substrate for film formation
713: Heater for substrate heating
714: Vacuum pump for gas exhaust
715: radiation blocking member

Claims (6)

A raw material gas containing a gas containing Si and / or C in a molecular formula, and a non-Si non- gas consisting of a gas not containing Si and C in a molecular formula heated by a first thermal catalyst disposed in a gas introduction path. The C-based gas is separated from the plurality of gas ejection ports provided in a shower head serving also as a plasma generation electrode provided in the film formation space and is separated from the gas supply holes, and is separated into the film formation space. The gas that has been ejected and mixed is decomposed and activated by the plasma generated by the shower head connected to a high-frequency power supply, and a film is deposited on a substrate disposed in the film formation space so as to face the shower head. A second thermal catalyst, which is different from the thermal catalyst disposed in the non-Si non-C-based gas introduction path, is disposed in the film forming space. hand The cleaning gas containing at least one of hydrogen gas, a gas containing fluorine (F) in the molecular formula, or a gas containing chlorine (Cl) in the molecular formula contains at least the non-Si non-C-based gas. The film is introduced into the deposition space through a passage, heated and activated by the first and second thermal catalysts, and the heated and activated gas forms the deposition chamber. A Cat-PECVD apparatus, comprising: a cleaning mechanism for etching and removing deposits deposited on the substrate. A raw material gas containing a gas containing Si and / or C in a molecular formula, and a non-Si non- gas consisting of a gas not containing Si and C in a molecular formula heated by a first thermal catalyst disposed in a gas introduction path. The C-based gas is separated from the film-forming space through a plurality of gas ejection ports provided in the antenna electrode through the hollow portion of the antenna electrode having a hollow structure installed in the film-forming space in a state where they are separated from each other. The gas that has been ejected and mixed into the film-forming space is decomposed and activated by plasma generated by the antenna electrode connected to a high-frequency power supply, and faces the antenna electrode in the film-forming space. A Cat-PECVD apparatus in which a film is deposited on a substrate disposed in a manner different from the thermal catalyst disposed in the non-Si non-C-based gas introduction path. Is the film forming And a cleaning gas containing at least one of a hydrogen gas, a gas containing fluorine (F) in a molecular formula, or a gas containing chlorine (Cl) in a molecular formula, The film is introduced into the film formation space through a Si non-C-based gas introduction path, heated and activated by the first and second thermal catalysts, and is heated and activated by the heated and activated gas. A Cat-PECVD apparatus, comprising: a cleaning mechanism for etching and removing deposits deposited in a film forming chamber constituting the apparatus. The gas containing fluorine (F) in the molecular formula or the gas containing chlorine (Cl) in the molecular formula is SF ₆ , NF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , CCl ₄ , C ₂ ClF. The Cat-PECVD apparatus according to claim 1, wherein the Cat-PECVD apparatus includes at least one of: ₅ , ClF ₃ , and CCIF ₃ . A film processing system comprising a plurality of vacuum chambers including at least one film forming chamber comprising the Cat-PECVD apparatus according to claim 1, wherein the film forming chamber is formed of a Si-based film or a C-based film. A film processing system having a structure capable of introducing at least one of a doping gas that can be converted into a type and a doping gas that can be converted into an n-type. 5. The film processing system according to claim 4, wherein at least two films having different conductivity types are stacked among a p-type film, a substantially i-type film, and an n-type film. 6. A film processing system comprising: cleaning a film forming chamber with a cleaning gas at least immediately before forming an i-type film when forming a film. In the film processing system according to any one of claims 4 to 5, an evacuation chamber, which is separated by a vacuum valve and can store a substrate, is adjacent to the film forming chamber including the Cat-PECVD apparatus according to any one of claims 1 to 3. A membrane processing system, which is provided.

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