JP2009062579A - Film deposition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film deposition system capable of suppressing generation of abnormal discharge, normally depositing a thin film, and enhancing the yield. <P>SOLUTION: The film deposition system comprises a film deposition chamber 2 which is a space for performing the film deposition, a first electrode 4 and a second electrode 5 arranged in the film deposition chamber, a mechanism constituted of a high frequency power source and a matching circuit to supply the power to one of the first electrode 4 and the second electrode 5 from the outside of the film deposition chamber 2, a mechanism to supply the power to the other of the first electrode 4 and the second electrode 5 from the outside of the film deposition chamber 2 or to be connected to the ground potential, a mechanism which allows gas to flow into between the first electrode 4 and the second electrode 5 and supplies the power to form plasma, and heats the film deposition chamber 2 so as to perform the film deposition by using the plasma, and a plurality of deposition-preventive plates 6 arranged corresponding to a plurality of side face parts in the film deposition chamber 2 so as to surround the film deposition chamber 2. The deposition-preventive plate 6 is divided into a plurality of portions, and spaces 6a, 6b are formed between the deposition-preventive plates 6 close to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a film forming apparatus provided with a film forming chamber for forming a film using plasma.

A film forming apparatus for forming a thin film on the surface of a product is used in many products such as manufacturing a solar cell module. Particularly in a solar cell module, when a photoelectric conversion layer or the like is formed on a film substrate or the like, a plasma CVD (Chemical Vapor Deposition) technique is used, and the film substrate is formed in a film forming chamber provided in a film forming apparatus. A Si-based thin film is formed thereon to form a photoelectric conversion layer. Specifically, a Si-based thin film or the like is formed on a film substrate by filling a vacuum deposition chamber with a film-forming gas such as Si (eg, SiH ₄ ) and performing plasma discharge. At this time, since a thin film may adhere to the inner wall of the film forming chamber, an adhesion preventing plate is disposed so as to cover the inner wall.

  Moreover, the roll-to-roll system and the stepping roll system are adopted for the film-formation apparatus for the film-like solar cell module. Here, the structure of the film forming apparatus will be described in detail. The film forming apparatus includes an unwinding core and a winding core, and the unwinding core and the winding core are spaced apart in the transport direction of the film substrate. It is arranged in the space. The film substrate is unwound from the unwinding core, wound up by the winding core, and conveyed in the film forming apparatus. In the film forming apparatus, a film forming chamber is arranged in a section between the unwinding core and the winding core, and the film substrate passes through the film forming chamber and is formed in the film forming chamber. The Rukoto. Therefore, the film formation chamber is required to have a simple structure that is easy to reinforce, enhances hermeticity in order to maintain a vacuum state, corresponding to the shape of the film substrate that passes through the film formation chamber. It is formed in a substantially rectangular parallelepiped. Further, the deposition preventing plate is disposed so as to correspond to the inner wall of the film forming chamber formed in a substantially rectangular parallelepiped. The structure of such a film forming apparatus is disclosed in Patent Document 1.

  In the process of forming a thin film using such an apparatus, first, in order to make the inside of the film forming chamber into a certain vacuum state, evacuation is performed by a mechanism of a gas exhaust system provided in the film forming apparatus. The substrate is heated by a heater provided in the film forming apparatus to perform degassing. After this degassing, in some cases, a mixed gas in which several kinds of film forming gases are mixed at an appropriate flow ratio is allowed to flow into the film forming chamber from the gas introduction line provided in the film forming apparatus, and is provided in the film forming apparatus. A thin film is formed on the substrate by maintaining an appropriate pressure in the film forming chamber with the pressure controller and applying power to the high frequency electrodes to generate plasma between the electrodes. Through such a process, for example, it is possible to form a multilayer film on a substrate under various film forming conditions to manufacture a thin film solar cell or the like.

Immediately after evacuation in this process, moisture or the like is often adsorbed on the film formation chamber or the surface of the substrate. When a thin film is formed in a state where these impurities are not sufficiently degassed, a large amount of impurities are contained in the thin film, which may lead to deterioration in film quality. Therefore, for the purpose of promoting degassing in the deposition chamber, gas is introduced from the gas introduction line into the deposition chamber before the thin film is formed, and the deposition chamber is maintained at a constant pressure by the pressure controller and the gas exhaust line. Then, heating (baking) in the film formation chamber is performed for several hours. During this heating, the gas that flows into the film formation chamber includes a gas having good thermal conductivity such as H ₂ , an inert gas such as He and Ar, or a film formation gas that flows into the film formation chamber during film formation. Etc. are adopted.
JP 2006-144091 A

  The film forming chamber of the film forming apparatus disclosed in Patent Document 1 has a substantially rectangular parallelepiped shape, is surrounded by adjacent inner walls, and has corners whose shape changes abruptly. The plasma discharge uses plasma generated by high-frequency power, and is likely to cause abnormal discharge at locations where the shape changes rapidly, such as protrusions and depressions. When abnormal discharge occurs, there is a problem that the thin film is not formed normally and the yield is lowered.

  Particularly, in a film forming apparatus for forming a Si-based thin film on a substrate by plasma, the temperature heated by the heater is often set to about 100 ° C. to 350 ° C., and the inner wall and the deposition plate forming the film forming chamber are It is heated by radiation from the heater and heat transfer from the gas. Therefore, the components of the film formation chamber are required to ensure the stability of the shape and the like against heat. If this stability is not ensured, deformation of the deposition plate, etc. will occur during film formation, resulting in the formation of protrusions and depressions whose shape changes rapidly, causing abnormal discharge, and the thin film There is a problem that it is not formed normally and the yield decreases.

  In addition, in order to ensure thermal stability, the Si-based thin film is plasma on the substrate when the components of the deposition chamber other than the heater, such as the inner wall of the deposition chamber and the deposition plate, are cooled by cooling water or the like. And a large amount of powdery by-products are formed in the cooled portion. When this by-product is mixed in the thin film formed on the substrate, the thin film is not formed normally, and the yield rate is significantly reduced.

  Therefore, an object of the present invention is to provide a film forming apparatus that suppresses the occurrence of abnormal discharge, forms a thin film normally, and improves the yield.

  In order to solve the problem, a film forming apparatus according to the present invention includes a film forming chamber which is a space for film forming, a first electrode and a second electrode disposed in the film forming chamber, a high-frequency power source, A mechanism configured of a matching circuit and supplying power from one outside of the film formation chamber to one of the first electrode and the second electrode; and of the first electrode and the second electrode Electricity is supplied to the other electrode from the outside of the film formation chamber or connected to the ground electrode, and gas is supplied between the first electrode and the second electrode to supply the electrode. And a mechanism for heating the film formation chamber so as to form a film using the plasma, and a plurality of side surfaces disposed in the film formation chamber so as to surround the film formation chamber. A plurality of deposition preventing plates, and the deposition preventing apparatus. Was divided into a plurality, it is characterized in that a gap is provided between the deposition preventing plate between adjacent.

  In the film forming apparatus of the present invention, an end portion of the deposition preventing plate may be curved at a portion corresponding to a corner portion in the film forming chamber.

  In the film forming apparatus according to the present invention, the first electrode plate or the first electrode plate and the second electrode plate are formed between a peripheral portion of the first electrode plate and the end portions of the deposition preventing plate. In the film forming apparatus in which the distance to the straight line portion is X, the end portion of the curved deposition preventing plate, the first electrode plate or the first electrode plate, and the second electrode plate The end portion may be formed such that the distance between and is 0.95X to 1.05X.

  In the film forming apparatus of the present invention, the deposition preventing plate may be made of an insulator.

  In the film forming apparatus of the present invention, the end of the deposition preventing plate exposed to the plasma may be chamfered or rounded.

  In the film forming apparatus of the present invention, a corner portion of the electrode plate adjacent to the end portion of the deposition preventing plate disposed at a portion corresponding to the corner portion in the film forming chamber has a chamfered shape or an R shape. Also good.

  In the film forming apparatus of the present invention, only the side surface exposed to the plasma of the deposition preventing plate may be processed so as to have an uneven shape.

  In the film forming apparatus of the present invention, the side portions on both sides of the deposition preventing plate may be processed so as to have an uneven shape.

  In the film forming apparatus of the present invention, the uneven shape may be formed in a substantially circular shape having a diameter of 5 μm to 200 μm when viewed from the side surface portion of the deposition preventing plate.

  According to the film forming apparatus of the present invention, the following effects can be obtained. That is, in the film forming apparatus of the present invention, the inner plate of the film forming chamber and the deposition preventing plate are heated by dividing the deposition preventing plate into a plurality of portions and providing a gap between the neighboring deposition preventing plates. In this state, it is possible to ensure escape from thermal expansion of the deposition preventing plate, and it is possible to suppress formation of protrusions and depressions due to thermal deformation. Further, by reducing the area per one of the deposition preventing plates, it is possible to suppress the deformation amount due to thermal expansion when heated. Further, by reducing the number of fixtures such as screws for suppressing thermal deformation, it is possible to shorten the maintenance time such as attachment / removal.

  In the high frequency discharge in which the end of the deposition preventing plate may be curved at a portion corresponding to the corner in the film forming chamber, and the discharge tends to concentrate on a portion where the shape changes rapidly, such as the corner. The occurrence of abnormal discharge can be reduced by reducing the rapidly changing portion in the membrane chamber.

  The distance between the peripheral portion of the first electrode plate or the peripheral portion of the first electrode plate and the second electrode plate and the straight portion formed between the end portions of the deposition preventing plate is X. In the film forming apparatus, the distance between the end portion of the curved deposition preventing plate and the first electrode plate or the first electrode plate and the second electrode plate is 0.95X to 1.05X. The end portion may be formed so that the distance between the electrode plate and the deposition preventing plate can be easily maintained uniformly throughout the film forming chamber. The distance between the high-frequency electrode and the part having the ground potential affects the ease of discharge, and if this distance is different from other parts, a phenomenon such as the concentration of discharge or the inability to discharge can occur in this part, and the plasma Uniformity will deteriorate. This is because the deterioration of the plasma uniformity becomes a factor that deteriorates the uniformity of the film pressure of the thin film formed on the substrate.

  The deposition plate may be made of an insulator, and high frequency discharge is not applied to the deposition plate itself, and abnormal discharge due to the shape of the end of the deposition plate can be suppressed. Become.

  The end of the adhesion-preventing plate exposed to plasma may be chamfered or rounded, and the square-shaped portion of the entire adhesion-preventing plate is reduced, resulting in abnormal discharge. It is possible to reduce the rapidly changing portion.

  A corner portion of the electrode plate adjacent to the end portion of the deposition plate disposed at a portion corresponding to the corner portion in the film forming chamber may be chamfered or R-shaped. The distance between the first electrode plate and the second electrode plate at the corner portion and the deposition preventing plate is 0.95 times the distance between the rectilinear portion of the deposition preventing plate and the rectilinear portion of the electrode plate. It becomes easy to keep 1.05 times, and it becomes possible to suppress the change of the discharge environment at the corner of the film forming chamber.

  Only the side surface exposed to the plasma of the deposition preventive plate may be processed so as to have a concavo-convex shape, and peeling of the thin film formed on the deposition preventive plate can be suppressed. In the case of such an adhesion-preventing plate having a concavo-convex shape on only one surface, deformation such as warpage is likely to occur when the proofing plate itself forms an uneven shape. This tendency becomes prominent particularly when the thickness of the deposition preventing plate is reduced.

  Side surfaces on both sides of the deposition preventive plate may be processed so as to have a concavo-convex shape, and by providing the concavo-convex shape on the side not exposed to plasma, internal stress in the deposition preventive plate is generated when the concavo-convex shape is formed. Therefore, even if the process of removing the adhesion film on the adhesion-preventing plate such as blasting is repeated several times, the shape of the adhesion-preventing plate can be kept linear or planar.

  The concavo-convex shape may be formed in a substantially circular shape having a diameter of 5 μm to 200 μm when viewed from the side surface portion of the deposition preventing plate, and the peel strength of the film attached to the deposition preventing plate can be increased.

  A first embodiment of the present invention will be described below. FIG. 1 schematically shows the inside of the film forming apparatus 1. Inside the film forming apparatus 1, a substantially rectangular parallelepiped film forming chamber 2 is arranged, and the film substrate 3 to be processed is arranged so as to be conveyed along the conveying direction A. An inlet opening 2a and an outlet opening 2b are provided at a substantially central height of the film forming chamber 2, and the film substrate 3 is inserted from the inlet opening 2a, passes through the film forming chamber 2, and is discharged from the outlet opening 2b. Has been. A high-frequency electrode (corresponding to a first electrode) 4 and a ground electrode (corresponding to a second electrode) 5 each including a high-frequency power source and a matching circuit are provided inside the film forming chamber 2. The high frequency electrode 4 includes a mechanism for supplying electric power from the outside of the film forming chamber 2 and is disposed on one surface side of the film substrate 3. The ground electrode 5 is disposed on the other surface side of the film substrate 3. Further, a heater (not shown) for heating the substrate is provided in the ground electrode 5 and is disposed on the other surface side of the film substrate 3. The inner wall on the ground electrode 5 side of the film forming chamber 2 is provided with a mechanism that operates in a direction approaching the film substrate 3, and when forming a photoelectric conversion element or the like on the film substrate 3, the inner wall of the film forming chamber 2 is provided. Then, the substrate 3 is sandwiched between them, and a film forming gas is filled in a state where the film forming chamber 2 is isolated from the outside, and high frequency power is applied to the high frequency electrode 4 to generate plasma from the high frequency electrode 4 to the ground electrode 5.

  FIG. 2 shows a cross-sectional view of the film forming apparatus 1 shown in FIG. A substantially rectangular high-frequency electrode 4 is disposed at a substantially central portion of the film forming apparatus 1, and an adhesion preventing plate 6 is disposed corresponding to the four inner walls of the film forming chamber 2. The adhesion preventing plates 6 arranged on the respective side portions of the film forming chamber 2 are divided into two as seen from the BB cross section of FIG. 2, and the film forming chambers are formed between the adhesion preventing plates 6 and 6 at room temperature. There are a gap 6a in the straight line portion 2 and a gap 6b in the corner portion of the film forming chamber 2. When heating the inside of the film forming chamber 2, the adhesion preventing plate 6 narrows the gaps 6 a and 6 b between the adhesion preventing plates 6 and 6 due to a difference from a member constituting the film forming chamber 2 or a difference in heat capacity. Will grow. When forming a thin film solar cell, it is necessary to form a laminated film composed of a plurality of thin films on a substrate. The film forming apparatus 1 includes a film forming chamber 2 for forming various thin films, a deposition plate 6, and the like, each having a different heater temperature, gas pressure, and the like. The temperature is different. It is preferable to set so that the gaps 6a and 6b between the deposition preventing plates 6 and 6 are eliminated in a thermal equilibrium state at the start of film formation after heating.

  Further, by applying a deposition plate 6 having a heat resistance equal to or higher than the temperature reached in the film formation chamber 2 and formed of an insulating material, a discharge is generated between the high-frequency electrode 4 and the deposition plate 6. It becomes the structure which does not generate | occur | produce and it becomes possible to suppress abnormal discharge.

  As a first modification of the first embodiment, the gaps 6a and 6b between the adhesion preventing plates 6 and 6 are set to 1/10 or less of the distance between the high-frequency electrode 4 and the ground electrode 5 (interelectrode distance). good. Therefore, it is preferable that the gaps 6a and 6b between the deposition preventing plates 6 and 6 at room temperature have different values according to the use environment of each film forming chamber 2 or the like.

  Further, as a second modification of the first embodiment, the number of divisions of the deposition preventing plate 6 in the side surface portion of the film forming chamber 2 does not have to be 2, and may be 3 or more. Further, the number of divisions does not need to be the same for the side surfaces of all the film forming chambers 2. For example, considering the ease of attachment, the number of divisions of the side portions that are difficult to attach is low, and the number of divisions of the side portions that are easy to attach May be high.

  By providing such a deposition preventing plate 6 in the film forming chamber 2, it is possible to reduce the projection generating elements accompanying the thermal expansion of the deposition preventing plate 6 when the deposition chamber 2 is heated. It is possible to reduce the number of occurrences of discharge.

  FIG. 3 is a view showing the deposition preventing plate 6 and the film forming chamber 2 in the second embodiment of the present invention. In the second embodiment, the basic structure is the same as that of the first embodiment, the first modified example or the second modified example of the first embodiment, and different parts will be described below. Specifically, the end 6d of the deposition preventing plate 6 is curved at the portion corresponding to the corner in the film forming chamber 2, and the end 6d of the deposition preventing plate 6 is disposed close to the end 6d. The two adhesion preventing plates 6 and 6 adjacent to each other are integrated with each other in accordance with the curved shape of the end 6d while leaving a gap 6b to form one curved shape. Further, the gap 6b is set at such an interval that the two adjacent anti-adhesion plates 6 and 6 do not contact each other even when the anti-adhesion plate 6 undergoes linear expansion at a high temperature.

  By adopting such a configuration, it is possible to reduce the number of places where the shape suddenly changes in the film forming chamber 2, and it is possible to reduce the number of occurrences of abnormal discharge. As in the first embodiment, the gap 6b between the deposition preventing plates 6 and 6 is preferably set to a distance that eliminates the gap in the thermal equilibrium state at the start of film formation after heating.

  Further, the distance between the straight portion 4a of the high-frequency electrode 4 disposed between the pair of corners of the film forming chamber 2 and the straight portion 6c of the deposition preventing plate 6 is X (X in FIGS. 3 and 4). By changing the curvature of the curved portion provided in the deposition plate 6 in the deposition apparatus 1, the distance D between the high-frequency electrode 4 and the deposition plate 6 at the corner of the deposition chamber 2 (in FIGS. 3 and 4). When D) is set to 0.95X to 1.05X, the uniformity of the film pressure is improved by about ± 5% as compared with the case where 0.9X and 1.1X are set.

  As a modification of the second embodiment, when it is difficult to eliminate the gap 6b in the thermal equilibrium state between the butted portions of the adhesion preventing plates 6 and 6, the end portion having the bending portion of the adhesion preventing plate 6 The vicinity of 6d may be strongly fixed to the inner wall of the film formation chamber 2 as compared with other portions, and the other end 6d having no curved portion may be preferentially expanded by thermal expansion.

  FIG. 4 shows the high-frequency electrode 4 and the deposition preventing plate 6 in the third embodiment of the present invention. In the third embodiment, the basic structure is the same as that of the second embodiment or the modified example of the second embodiment, and parts different from the second embodiment will be described below. Specifically, the corner 4 b of the high-frequency electrode 4 and the end 6 d of the deposition preventing plate 6 disposed at the corner of the film formation chamber 2 are curved. With this configuration, the distance D between the corner 4b of the high-frequency electrode 4 and the end 6d having the curved portion of the deposition preventing plate 6 can be easily maintained at 0.95X to 1.05X, and the film pressure is uniform. It is easy to ensure the property. In addition, since the protrusions of the high-frequency electrode 4 are reduced, the number of occurrences of abnormal discharge can be suppressed.

  Furthermore, a fourth embodiment of the present invention will be described. Fig.5 (a) has shown the adhesion prevention board 6 of 1st embodiment among the adhesion prevention boards 6 of 1st embodiment-3rd embodiment shown to FIGS. 2-4 as a representative example. Specifically, the end 6d of the deposition preventing plate 6 shown in FIG. 5A has a shape having an acute corner. In the fourth embodiment, the basic structure is the same as that of any one of the first to third embodiments (including the respective modifications), and differences from these will be described. As shown in FIG.5 (b), the edge part 6d of the adhesion prevention board 6 shown to the BB cross section of FIG. 2 is made into the chamfering shape. This chamfered portion is preferably performed at all of the end portion 6d on the side exposed to the plasma, and abnormal discharge can be prevented. Alternatively, this chamfered shape may be an R shape, and the same effect can be obtained.

  As a modification of the fourth embodiment, the film forming chamber 2 is exposed to either the front or back side of the deposition preventing plate 6 by exposing the side not exposed to the plasma to a chamfered end 6d of the deposition preventing plate 6. Therefore, it becomes possible to use both the front and back sides of the deposition preventive plate 6 and to make effective use of the deposition preventive plate 6.

  In addition, a fifth embodiment of the present invention will be described. Fig.6 (a) has shown the adhesion prevention board 6 of 2nd embodiment-3rd embodiment. Specifically, the end 6d of the deposition preventing plate 6 shown in FIG. 6A has a shape having an acute corner. In the fifth embodiment, the basic structure is the same as that of either the second embodiment or the third embodiment (including the respective modifications), and differences from these will be described. As shown in FIG.6 (b), the edge part 6d of the adhesion prevention board 6 in the C section of FIG. 3 is made into the chamfering shape. By using the deposition preventing plate 6 having the configuration as shown in FIG. 6B, it is possible to prevent the occurrence of abnormal discharge. Further, this chamfered shape may be an R shape, and the same effect can be obtained.

  A sixth embodiment of the present invention will be described. The basic configuration of the sixth embodiment is the same as that of any one of the first to fifth embodiments (including the respective modifications), and differences from these will be described below. In the side surface portion of the deposition preventive plate 6 that has been subjected to measures against thermal expansion and abnormal discharge as described above, a concavo-convex shape is provided by blasting only on the side exposed to the plasma. As a result, it is difficult for the film attached to the deposition preventing plate 6 to peel off, and the yield rate of thin film solar cells can be improved.

  Furthermore, the concave-convex shape seen from the side surface portion of the deposition preventing plate 6 is a substantially circular shape. By setting the diameter of this substantially circular shape to 5 μm or more, the thin film adhered to the deposition preventing plate 6 during the film formation. It becomes possible to reduce peeling from the deposition preventing plate 6. Specifically, the thickness is preferably 5 μm to 200 μm, and the peeling of the thin film attached to the deposition preventing plate 6 from the deposition preventing plate 6 can be further reduced. The degree of unevenness of the deposition preventing plate 6 is more preferably about 5 μm to 100 μm.

  Further, as a modification of the sixth embodiment, the uneven shape may be provided not only on the side of the deposition preventing plate 6 exposed to the plasma but also on the side of the deposition preventing plate 6 not exposed to the plasma. It is possible to suppress the warpage or deformation of the 6 itself. Further, by forming the concave and convex shapes on the side surface portions on both sides, the side surface portions on both sides of the deposition preventing plate 6 can be used, and the deposition preventing plate 6 can be effectively used.

  Although only the detailed shape of the high-frequency electrode 4 has been described in the above-described embodiment, the ground electrode 5 may be the same shape as the high-frequency electrode 4, or only the ground electrode 5 may be the shape of the high-frequency electrode 4 described above.

It is the outline which looked at the internal structure of the film-forming apparatus in embodiment of this invention from the side surface of the conveyance direction of a film substrate. It is the figure which looked at the film-forming apparatus in 1st embodiment of this invention in the BB cross section of FIG. It is the figure which looked at the film-forming apparatus in 2nd embodiment of this invention in the BB cross section of FIG. It is the figure which looked at the film-forming apparatus in 3rd embodiment of this invention in the BB cross section of FIG. (A) It is the figure which expanded and represented the adhesion prevention board of FIG. (B) It is the figure which represented the adhesion prevention board in 4th embodiment of this invention similarly to Fig.5 (a). (A) It is the figure showing the C section of FIG. 3 and FIG. (B) It is the figure showing the adhesion prevention board in 5th embodiment of this invention similarly to Fig.6 (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 2 Film-forming chamber 2a Inlet opening 2b Outlet opening 3 Film substrate 4 High frequency electrode (1st electrode)
4a Straight portion 4b Corner portion 5 Ground electrode (second electrode)
6 Protection plate 6a, 6b Gap 6c Straight line 6d End A Transport direction X Distance D Distance

Claims (9)

A film formation chamber which is a space for film formation, a first electrode and a second electrode arranged in the film formation chamber, a high frequency power source and a matching circuit, and the first electrode and the A mechanism for supplying electric power to one of the second electrodes from the outside of the film formation chamber, and electric power to the other electrode of the first electrode and the second electrode are supplied from the outside of the film formation chamber. Alternatively, a plasma is formed by supplying a gas by flowing a gas between the first electrode and the second electrode and a mechanism connected to the ground potential, and using the plasma to form a film A mechanism for heating the film formation chamber so as to perform a plurality of deposition plates, and a plurality of deposition plates arranged corresponding to a plurality of side surface portions in the film formation chamber so as to surround the film formation chamber. In the film forming apparatus,
The deposition apparatus according to claim 1, wherein the deposition preventing plate is divided into a plurality of portions, and a gap is provided between the deposition preventing plates adjacent to each other.   The film forming apparatus according to claim 1, wherein an end portion of the deposition preventing plate is curved at a portion corresponding to a corner portion in the film forming chamber. The distance between the peripheral edge portion of the first electrode plate or the peripheral edge portions of the first electrode plate and the second electrode plate and the linear portion formed between the end portions of the deposition preventing plate is X In the film forming apparatus
The end so that a distance between the bent end portion of the deposition preventing plate and the first electrode plate or the first electrode plate and the second electrode plate is 0.95X to 1.05X. The film forming apparatus according to claim 1, wherein a portion is formed.   The film forming apparatus according to claim 1, wherein the deposition preventing plate is made of an insulator.   5. The film forming apparatus according to claim 1, wherein an end of the deposition preventing plate exposed to plasma has a chamfered shape or an R shape.   2. The corner portion of the electrode plate adjacent to the end portion of the deposition preventing plate disposed at a portion corresponding to the corner portion in the film forming chamber is chamfered or R-shaped. The film-forming apparatus as described in any one of -4.   The film forming apparatus according to claim 1, wherein only the side surface exposed to the plasma of the deposition preventing plate is processed so as to have an uneven shape.   The film forming apparatus according to claim 1, wherein side surfaces on both sides of the deposition preventing plate are processed so as to have an uneven shape.   The film forming apparatus according to claim 7, wherein the uneven shape is formed in a substantially circular shape having a diameter of 5 μm to 200 μm when viewed from the side surface portion of the deposition preventing plate.

Images