JP3063497B2 - Manufacturing equipment for thin-film photoelectric conversion elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a thin film photoelectric conversion element in which each layer is formed on a flexible substrate by a stepping roll method.

[0002]

2. Description of the Related Art For example, amorphous silicon (hereinafter a-
A method for manufacturing a thin-film photoelectric conversion element by forming each layer including a photoelectric conversion layer whose main material is Si) on a flexible substrate made of a long polymer material or a metal such as stainless steel is a production method. Excellent in terms of sex. A roll-to-roll method in which a plurality of layers are formed on a long flexible substrate and a film is formed on a substrate moving in each film forming chamber, and a film is formed on a substrate stopped in the film forming chamber Then, there is a stepping roll method in which the substrate portion on which film formation has been completed is sent out of the film formation chamber. In the stepping roll method in which a film is formed by using the plasma CVD method, a film forming chamber is opened, a substrate is moved by one frame, a film forming chamber is sealed, a source gas is introduced, a pressure control is performed, a discharge is started, a discharge is completed, a source gas is stopped, and a gas is drawn. The operation of opening the film formation chamber is repeated.

A film forming apparatus employing this step roll method is superior to the usual roll-to-roll film forming in the following points. (1) There is no gas mutual diffusion with the adjacent deposition chamber. (2) The device is compact. 2A and 2B show cross sections of the stepping roll type film forming chamber when the film forming chamber is opened and when it is sealed, respectively. A lower film-forming chamber 21 and an upper film-forming chamber 22 having a box shape face each other above and below the flexible substrate 1 conveyed intermittently. Power supply 4 in lower film formation chamber 21
The high voltage electrode 31 connected to the
A built-in ground electrode 32 is provided. During film formation,
As shown in FIG. 2B, the upper film forming chamber 22 descends, and the ground electrode 32 holds down the substrate 1 and contacts the sealing material 5 attached to the opening-side end face of the lower film forming chamber 21. As a result, an airtightly sealed film-forming space 6 communicating with the exhaust pipe 61 is formed by the lower film-forming chamber 21 and the substrate 1, and a plasma is generated in the film-forming space 6 by applying a high-frequency voltage to the high-voltage electrode 31. To decompose the raw material gas introduced from an introduction pipe (not shown) to
A film is formed thereon. In this case, the sealing material 5 comes into contact with the end of the wall surface of the upper film forming chamber 22 heated by the heater 33 via a flexible substrate having a thickness of several tens to several hundreds of microns. The temperature of the portion is substantially equal to the wall surface of the upper film forming chamber 22. The heater temperature during film formation is 200 to 300 ° C, while
When a fluorine rubber or the like is used as the sealing material 5, the sealing portion needs to be kept at 150 ° C. or lower in order to prevent degassing. For this reason, it is important to keep the temperature of the wall surface of the upper film forming chamber 22 at 150 ° C. or less, and a space of at least 2 mm, preferably 5 mm or more is provided between the ground electrode 32 and the wall surface of the upper film forming chamber 22. There is a need.

[0004]

At the time of the film formation shown in FIG. 2B, a space 62 surrounded by the upper film formation chamber 22 and the substrate 1 is generated. However, as described in the specification of Japanese Patent Application No. 347394 and the like of the applicant of the present invention, the transparent electrode layer of the thin film photoelectric conversion element formed on one surface of the substrate and the other surface are formed on the other surface. A structure has been developed in which the formed metal electrode layer is connected to a transparent electrode layer having a high sheet resistance by connecting the formed metal electrode layer via a conductor passing through a through-hole formed in the substrate. When such a thin film of the photoelectric conversion element is formed by the apparatus shown in FIG. 2, the spaces 6 and 62 on both sides of the substrate 1 communicate with each other through the through-holes that have already been formed in the substrate 1. Become. This causes the following problems. (1) The source gas enters and accumulates in the space 62 in the upper film forming chamber 22 through the through hole. If the accumulated gas or the space 62 is not hermetically sealed, the gas mixed with the atmosphere reversely diffuses into the film formation space 6 and adversely affects the film formation. (2) When two or more types of films are formed in one film forming chamber,
The second layer is formed before the gas accumulated in the space 62 is cut off after the first layer is formed. For this reason, when the first layer is a p-type or n-type doped film, the impurity is mixed into the second layer, and a film having different characteristics such as conductivity and optical gap from the film originally intended. Can be done.

Further, as the area of the flexible substrate 1 increases, the area of the film forming chamber also increases. However, a high vacuum is applied so that the wall of the film forming chamber and the thin flexible substrate having a large area are not wrinkled. Is difficult to seal. Further, if the space between the ground electrode 32 and the wall surface of the upper film formation chamber 22 is made as small as possible to reduce the area of the film formation chamber, the temperature of the wall surface becomes 25
May exceed 0 ° C. As the sealing material having a heat resistance of 250 ° C. or more, asbestos-based or metal-based packing is generally used. However, these sealing materials have to increase the pressing pressure on the surface, and cannot be adopted in a structure in which the seal is repeatedly opened and closed. When a fluoro rubber or a fluoro resin is selected as a sealing material having a low pressing pressure on the surface, a temperature of 180 ° C. or less is a temperature that can be used for a long time.

[0006] Such a problem is not limited to the case where the film is formed by plasma CVD with the high voltage electrode facing the stopped flexible substrate, but the target is also set to face the stopped flexible substrate. It also exists when a film is formed by sputtering. The object of the present invention is to solve the above problems,
An apparatus for manufacturing a thin film photoelectric conversion element capable of forming a thin film with good characteristics on a flexible substrate having a through hole, and a sealing material capable of forming a large area and having a low pressing pressure can be used. An object of the present invention is to provide an apparatus for manufacturing a thin-film photoelectric conversion element.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a flexible substrate which is conveyed to two sides of a film forming chamber each having a box-shaped wall. And the substrate is sandwiched between the open end faces of the walls of both parts of the film formation chamber, and a film formation space surrounded by one part of the film formation chamber and the substrate is evacuated, and the electrodes in that space are evacuated. In a manufacturing apparatus for a thin-film photoelectric conversion element that applies a voltage to a film to form a film, a sealing material is provided on an opening-side end surface of a wall of each part of the film forming chamber, and a vacuum exhaust pipe is opened on the wall of each part. It shall be. It is effective that the sealing material on the opening side end surface of the wall body of each part of the film forming chamber is provided at a position not opposed to the substrate, and the sealing material is formed on the holding body fixed on the end surface. Good to be held in the groove. The side of the edge of the holder facing the substrate may be rounded off. It is preferable that the sealing material is a rectangular O-ring. It is effective that the vacuum exhaust pipes opening to the walls of the respective parts of the film forming chamber are connected by flexible piping. Further, it is preferable that the vicinity of the opening side end surface of the wall of the film forming chamber in which the counter electrode containing the heater is housed is water-cooled. It is effective to use a CVD method in which a source gas is introduced into a film forming space or a sputtering method in which a discharge gas is introduced.

[0008]

The flexible substrate is sandwiched between two parts having a box-like wall having a sealing material on the opening side end surface of the film forming chamber wall by the stepping roll method, and the space on both sides of the substrate can be evacuated. By doing so, even if a through-hole is formed in the substrate, if a raw material gas or a discharge gas enters the film formation chamber portion on the side opposite to the film formation chamber portion having the film formation space, it is exhausted, Impurities do not return to the film formation space to impair the characteristics of the film. Because the sealing materials on both sides of the substrate are not opposed to each other, when both parts of the film forming chamber are pressed against the substrate, the sealing materials do not wrinkle due to the displacement of the substrate due to the pressing of the sealing materials, and a large area is formed. A film-forming chamber having a film space can be hermetically sealed. When the film forming chamber is divided into the upper and lower parts, the sealing material of the upper film forming chamber falls, or when the film forming chamber is opened, the sealing material of the lower film forming chamber adheres to the substrate and rises. This can be prevented by holding the sealing material in the groove of the holder. Further, by rounding the edge of the holder, the substrate can be prevented from being damaged. By using a rectangular O-ring as a sealing material and making the film formation chamber rectangular, the area of the film formation space can be increased, and film formation on a large-area substrate becomes possible. Then, the wall of the film forming chamber near the sealing material is cooled with water,
A rise in the temperature of the sealing material can be prevented, and a sealing material having a low pressing pressure can be used.

[0009]

FIG. 1 shows an apparatus for manufacturing a thin film photoelectric conversion element for forming a film by a plasma CVD method according to one embodiment of the present invention.
2 are denoted by the same reference numerals. FIG.
Indicates that the film forming chamber is open, and the flexible substrate 1 is transported in a direction perpendicular to the paper surface. The lower film forming chamber 21 that houses the high-voltage electrode 31 includes a base 23 and a top plate 24 having an opening, and is connected to a vacuum exhaust pipe 61. The upper film forming chamber 22 that houses a heater (not shown) and a built-in ground electrode 32 includes a casing 25 and a housing 26, and a support tube 34 for the ground electrode 32 is fixed to the housing 26 by fitting.
A moving plate 27 is attached to an end of the housing 26. The moving plate 27 is guided by an up-down drive guide 28 and is driven up and down by an actuator 29 as shown by an arrow 30. Vertical drive guide 28 and actuator 29
Is fixed to a mount 35 and mounted on an upper flange 37 on a film forming chamber chamber 36. The support tube 34 has a cylindrical shape, and the internal cavity communicates with the vacuum exhaust pipe 63 at the upper end, and communicates with the internal space of the upper film forming chamber 22 through the through hole 36 at the lower end. The vacuum exhaust pipe 61 and the vacuum exhaust pipe 63 are connected by a flexible pipe 64.

FIG. 3 is an enlarged view of the seal portion. The O-ring 5 is formed by a metal holding plate 7 screwed on the upper surface of the top plate 24 and the lower end surface of the casing 25 and the top plate 24 or the casing 25.
It is held so that it does not fall into 71. The edge 72 of the holding plate 7 is chamfered so that when the upper film forming chamber 22 is lowered and the substrate 1 is sandwiched between the lower film forming chamber 21 and the substrate 1, care is taken not to damage the substrate. is there. FIG.
FIG. 5 is a plan view of the top plate 24 as viewed from above. The position of the O-ring 5 is near the outer edge of the holder 7 on the upper film forming chamber side, and is closer to the inner edge of the holder 7 on the lower film forming chamber side. Therefore, at the time of film formation, the O-ring 5 is pressed against the substrate 1 at different positions on the front and back, so that the substrate 1 does not wrinkle. A cooling water passage 8 is opened near the end face on the opening side of the casing 25, and water flows through a cooling water conduit 81. By this water flow, the end of the casing 25 is cooled, and O
The use of fluorine rubber or fluorine resin for the ring 5 is enabled. A water cooling jacket 82 is also formed on the support tube 34 connected to the ground electrode 32 containing a heater, and an arrow 83
The support tube 34 is cooled by the water flow shown in FIG.

FIG. 1 shows a state in which the substrate 1 is transported. During film formation, an actuator 29 operates to move a housing 26 fixed to a movable plate 27, a casing 25 fixed to the housing 26, a support tube 34, and a support tube 34. The supported ground electrode 32 descends and pushes down the substrate, and the lower film forming chamber 21 and the upper film forming chamber 22 are respectively held by both O-rings 5.
Is closed, and a vacuum space is formed in both chambers by the vacuum exhaust from the vacuum exhaust pipes 61 and 63. Thereby, the high voltage electrode 31
A high-frequency voltage applied to the film causes a film formation space 6 in which plasma is generated. The flexible pipe 64 is interposed between the vacuum exhaust pipes 61 and 63, and the bellows 38 that blocks the atmosphere is interposed between the moving plate 27 and the upper flange 37. The lowering of the chamber 22 is performed smoothly.

[0012]

According to the present invention, not only a film forming chamber portion including a film forming space in contact with one surface side of a flexible substrate at the time of film forming by a stepping roll method but also a ground electrode including a ground electrode in contact with the other surface side. By enabling vacuum evacuation of each of the film chamber portions, film formation on a substrate having a through hole can be performed without any trouble. By bringing the sealing material into contact with the two surfaces of the substrate at different positions, the sealing material can be sufficiently pressed against the substrate, the vacuum tightness on both surfaces of the substrate is ensured, and a film can be formed on a large-area substrate. . Water-cooling of the vicinity of the opening side end surface of the wall of the film forming chamber portion including the ground electrode including the built-in heater makes it possible to use a sealing material having a small pressing pressure and a low heat resistance, thereby further facilitating airtight maintenance. Was completed. These effects are due to
There is no difference between the case of performing by the VD method and the case of performing by the sputtering method.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a thin-film photoelectric conversion element manufacturing apparatus according to one embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views showing a film forming chamber of a conventional thin film photoelectric conversion device manufacturing apparatus, wherein FIG.

FIG. 3 is an enlarged sectional view showing the vicinity of a seal portion of the apparatus shown in FIG. 1;

FIG. 4 is a bottom view of the upper film forming chamber casing opening side end of the apparatus of FIG. 1;

FIG. 5 is a top view of a top plate of a lower film forming chamber of the apparatus of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible substrate 21 Lower film formation room 22 Upper film formation room 23 Base 24 Top plate 25 Casing 26 Housing 27 Moving plate 29 Actuator 31 High voltage electrode 32 Ground electrode 33 Heater 34 Support tube 5 O-ring 6 Film formation space 61, 63 Vacuum exhaust pipe 64 Flexible piping 7 Retaining plate 71 Recessed groove 8 Cooling water passage 81 Cooling water conduit 82 Water cooling jacket

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-12735 (JP, A) JP-A-62-13030 (JP, A) JP-A-5-251361 (JP, A) JP-A-60-1985 30124 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/205 H01L 21/203 H01L 31/04

Claims (9)

(57) [Claims] A flexible substrate to be transported is stopped between the opening sides of two portions each having a box-shaped wall in a film forming chamber, and the substrate is moved to the opposite side of the wall in both portions of the film forming chamber. A film forming space surrounded by one part of the film forming chamber and the substrate is sandwiched between the end faces on the opening side, and a film is formed by applying a voltage to the electrodes in the space. An apparatus for manufacturing a thin-film photoelectric conversion element, wherein a sealing material is provided on an opening-side end surface of a wall, and a vacuum exhaust pipe is opened on each wall. 2. The thin-film photoelectric conversion device manufacturing apparatus according to claim 1, wherein the sealing material on the opening-side end surface of the wall body of each part of the film forming chamber is provided at a position where the sealing material does not face the substrate. 3. The apparatus according to claim 1, wherein the sealing material is held in a groove formed in the holding body fixed on the end face. 4. The apparatus for manufacturing a thin film photoelectric conversion element according to claim 3, wherein the side of the edge of the holding body facing the substrate is rounded off. 5. The apparatus according to claim 1, wherein the sealing material is an O-ring. 6. The apparatus for manufacturing a thin-film photoelectric conversion device according to claim 1, wherein vacuum evacuation pipes opening to the walls of each part of the film forming chamber are connected by flexible pipes. 7. The vicinity of an opening-side end surface of a wall of a film forming chamber in which a counter electrode containing a heater is housed is water-cooled.
7. The apparatus for manufacturing a thin-film photoelectric conversion element according to any one of claims 6 to 6. 8. The apparatus for manufacturing a thin film photoelectric conversion element according to claim 1, wherein the film is formed by a CVD method in which a source gas is introduced into a film forming space. 9. The apparatus for manufacturing a thin film photoelectric conversion element according to claim 1, wherein the film is formed by a sputtering method in which a discharge gas is introduced into a film forming space.