JP3096698B2 - Method for manufacturing thin film photoelectric conversion element and film forming apparatus used for the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin-film photoelectric conversion element in which each layer is formed on a flexible substrate by a stepping roll method, and a film forming apparatus used in the 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, 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.
The operations of film formation chamber sealing, source gas introduction, pressure control, discharge start, discharge end, source gas stop, gas evacuation, and film formation chamber opening are repeated.

A film forming apparatus employing this stepping 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. FIGS. 2A and 2B show cross sections of the stepping roll type film forming chamber when the film forming chamber is opened and when the film forming chamber is sealed, respectively. A box-shaped lower film-forming chamber wall 21 and an upper film-forming chamber wall 22 are arranged above and below the intermittently transported flexible substrate 1. The lower film forming chamber is provided with a high voltage electrode 31 connected to the power supply 4, and the upper film forming chamber is provided with a ground electrode 32 having a built-in heater 33. At the time of film formation, as shown in FIG. 2B, the upper film formation chamber wall 22 is lowered, and the ground electrode 32 holds down the substrate 1 and the seal attached to the opening-side end face of the lower film formation chamber wall 21. Contact the material 5. As a result, an airtightly sealed film-forming space 6 communicating with the exhaust pipe 61 is formed by the lower film-forming chamber wall 21 and the substrate 1, and the plasma is formed by applying a high-frequency voltage to the high-voltage electrode 31. 6, a source gas introduced from an introduction pipe (not shown) is decomposed to form a film on the substrate 1.

At the time of the film formation shown in FIG. 2B, a space 62 surrounded by the upper film formation chamber wall 22 and the substrate 1 is generated.
However, as described in the specification of Japanese Patent Application No. 347394/1992, the transparent electrode layer of the thin film photoelectric conversion element formed on one surface of the substrate and the metal electrode layer formed on the other surface Are connected to each other via a conductor passing through a through-hole formed in the substrate, so that a current flowing distance of the transparent electrode layer having a high sheet resistance is shortened. 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 are already formed and dispersed in the substrate 1. Become. Therefore, the space 62 also needs to be kept airtight.
FIG. 3 shows the sealing structure of the lower and upper film forming chambers in such a case. Two band-shaped end plates 23 and 24 are provided on the end surface of the lower film forming chamber wall 21 and the upper film forming chamber wall 22 is formed. The two end strips 25 and 26 are screwed to the end face of
The seal material 5 is held in the dovetail groove formed therebetween so as not to fall off. At the time of film formation, the substrate 1 is provided with the surfaces of the end plates 23 and 24 on the lower film formation chamber side and the sealing material 5 therebetween,
By sandwiching the surfaces of the end plates 25 and 26 on the side of the upper film forming chamber and the sealing material 5 therebetween, the spaces 6 and 62 of the upper and lower film forming chambers are kept in a vacuum.

[0005]

When the area of the flexible substrate 1 becomes large, wrinkles occur when the conveyance is stopped. When a substrate with wrinkles is sandwiched between the upper film formation chamber and the lower film formation chamber, and the film is held under vacuum, the film formation pattern is shifted, and the characteristics of the manufactured thin film photoelectric conversion element are significantly reduced. There is a problem. Although various mechanisms that do not cause wrinkles are conceivable, there is also a problem that the apparatus becomes large.

An object of the present invention is to solve the above-mentioned problems and to provide a method of manufacturing a compact thin-film photoelectric conversion element capable of preventing the occurrence of wrinkles that occur when the transfer of a flexible substrate is stopped, and a film forming apparatus used in the method. To provide.

[0007]

According to a first aspect of the present invention, a flexible substrate is brought into close contact with an end surface around an opening of a box-shaped film forming chamber wall. In a method of manufacturing a thin film photoelectric conversion element, a film formation space surrounded by a wall and a substrate is evacuated, and a voltage is applied to electrodes housed in the space to form a thin film on the substrate. A method for manufacturing a thin-film photoelectric conversion element in which a wrinkle of a substrate is stretched by radially sliding an outer periphery of the substrate on an end surface around an opening of a film forming chamber wall, and wherein the outer periphery of the deposition surface of the substrate is provided. The tip of the elastic lip is pressed against the substrate, and the tip is slid outward with the substrate by frictional force, so that the outer periphery of the deposition surface of the substrate radiates on the end surface around the opening of the wall of the deposition chamber. To slide. Here, it is preferable that the sliding distance of the tip of the lip is set to 1/400 or more of the distance between the opposing sides of the lip in the sliding direction. Further, it is preferable to use a means for pressing the substrate toward the electrode by a pressing body located on the side opposite to the electrode, to extend wrinkles of the substrate. It is preferable to press the substrate until the substrate surface enters a depth of 2.0 to 2.5 mm inward from the opening surface of the film forming chamber wall. It is also possible to use a counter electrode of the electrode housed in the film formation space as the pressing body. Next, according to the second invention of the present invention, the flexible substrate is brought into close contact with the end surface around the opening of the box-shaped film forming chamber wall, and the film forming space surrounded by the wall and the substrate is evacuated. In a method of manufacturing a thin-film photoelectric conversion element in which a thin film is formed on a substrate by applying a voltage to an electrode housed in the space, the outer periphery of the film-forming surface of the substrate is formed on the end surface around the opening of the wall of the film-forming chamber. A method for manufacturing a thin-film photoelectric conversion element in which a wrinkle of a substrate is stretched by sliding radially to form a thin film photoelectric conversion element, wherein a means for pressing the substrate toward the electrode by a pressing body located on the opposite side to the electrode is provided. The wrinkles of the substrate are extended in combination with each other, and a counter electrode of the electrode housed in the film formation space is used as the pressing body. Also in this case, the substrate is preferably pressed until the substrate surface enters a depth of 2.0 to 2.5 mm inward from the opening surface of the film forming chamber wall. Next, according to the third invention of the present invention, as a film forming apparatus used in the method of manufacturing a thin-film photoelectric conversion element of the first invention,
A second wall that surrounds the film formation space, has an opening facing the opening of the box-shaped wall of the film formation chamber in which the electrode to which a voltage is applied is accommodated, and is drivable in a direction toward the film formation chamber wall; The end face of the box-shaped wall is provided with an elastic lip which is inclined outwardly with respect to the surface of the flexible substrate which is in close contact with the opening side of the wall of the film forming chamber. Here, the inclination angle of the lip with respect to the substrate surface is preferably 45 to 60 °. Preferably, the second wall is rectangular, and the lip is divided into four portions parallel to each of the sides parallel and perpendicular to the longitudinal direction of the rectangular substrate. It is also preferred that the lip is held on the end face of the second wall body by sandwiching the base between the packing material having an L-shaped cross section fixed to the end face and the holding material. It is also possible to provide an elastic O-ring on the end face of the film forming chamber wall body, facing the packing material on the end face of the second wall body. According to the fourth invention of the present invention, as a film forming apparatus used in the method of manufacturing a thin film photoelectric conversion element of the second invention, a box-like shape of a film forming chamber surrounding a film forming space and accommodating an electrode to which a voltage is applied is accommodated. An opposing electrode housed in a second box-shaped wall body having an opening facing the opening of the wall body and drivable in a direction toward the film forming chamber wall body is formed while pressing the substrate on its surface. It can be driven to the inside from the opening surface of the chamber wall.

[0008]

The wrinkles of a flexible substrate forming a film-forming space together with a box-like wall are slid radially around the film-forming surface of the substrate on the end surface of the film-forming chamber wall, and furthermore, the substrate is pressed. The film can be stretched by being pressed into the inside of the film-forming space by the body, and by forming the film in this state, the film-forming thickness becomes uniform and the generation of the film-forming pattern shift does not occur. To slide the outer periphery of the deposition surface of the substrate onto the end surface of the wall, the outer surface provided on the end surface of the second box-shaped wall having an opening facing the opening of the wall of the deposition chamber is directed outward. When the inclined elastic lip is brought into contact with the substrate surface by driving the second wall, and further slid outward, the frictional force generated between the substrate and the substrate causes the substrate to move outward. It can be realized because it can be spread. The height of the wrinkles is 3 to 5 mm, and the period of the wrinkles is about 80 mm, so that the wrinkles can be completely extended by sliding the substrate in the direction of the outer periphery of the film forming surface to about 1/200 of the dimension in one direction of the substrate. However, the effect appears at about 1/400 or more. If the angle of inclination of the lip is less than 45 °, the tip is less likely to slip outward,
If it exceeds 60 °, the frictional force with the substrate becomes small. In addition, if the lips are connected in a ring shape when the second wall is rectangular, deformation of the lips is prevented at the corners,
Divide into four parts parallel to each side of the rectangle. If the lip is held by sandwiching the base between the L-shaped packing material and the holding member on the end surface of the second wall, the deformed lip can be easily replaced, and the L-shaped packing can be easily replaced. The material can also make the space between the substrate and the end face of the second wall airtight. Also, an O face is formed on the end face of the film forming chamber wall facing the L-shaped packing material.
If a ring is provided, the film formation chamber can be hermetically sealed by the close contact between the substrate and the O-ring. If the depth of pressing the substrate from the opening surface of the film forming chamber wall is smaller than 2.0 mm, the wrinkles may not be sufficiently extended, and if it is larger than 2.5 mm, the substrate may be caught between the end faces of the two wall members. May not be able to support the wrinkles, making it difficult to stretch wrinkles. By using the counter electrode as the pressing body, an increase in the number of components of the film forming apparatus is reduced.

[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 an embodiment of the present invention, and the same reference numerals are given to the same parts as in FIG.
FIG. 1 shows a state in which the film forming chamber is opened, and the flexible substrate 1 is transported in a direction perpendicular to the paper surface. The lower film forming chamber for accommodating the high-voltage electrode 31 includes the wall 21 and the top plate 27 having an opening, and is connected to the vacuum exhaust pipe 61. An upper film forming chamber for accommodating a ground electrode 32 containing a heater (not shown) is composed of a wall 22 and a housing 28, and a support tube 34 of the ground electrode 32 is fitted to the housing 28 so as to be vertically movable. . A moving plate 29 is attached to an end of the housing 28. The moving plate 29 is guided by the vertical drive guide 30 and is driven by the actuator 41 in the vertical direction as indicated by the arrow 51. The vertical drive guide 30 and the actuator 41 are mounted on a mount 42.
And an upper flange 36 on a film forming chamber 35.
Is placed on top. 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 formation chamber through the through hole 37 at the lower end. The vacuum exhaust pipe 61 and the vacuum exhaust pipe 63 are connected by a flexible pipe 64. On the other hand, the support tube 34 of the ground electrode
Are actuators 44 fixed to the moving plate 29
Can move through the housing 28 via another moving plate 43, whereby the ground electrode 32 is driven in the vertical direction as shown by the arrow 52. A wrinkle-stretching structure is formed between the lower end of the wall 22 of the upper film forming chamber and the top plate 27 of the lower film forming chamber.

FIG. 4 shows a top plate 27 of the lower film forming chamber.
5 is a bottom view of an end of the upper film forming chamber wall 22. FIG. FIG. 6 shows the state when the film is released, and FIG.
FIG. 9 is a cross-sectional view of each of the wrinkle stretching structures when the film forming chamber is closed. On the portion near the opening 45 of the top plate 27, the sealing material 5 is held between the end plates 23 and 24 as shown in FIG. On the other hand, the base of a lip (lip-like body) 7 made of fluoro rubber is inserted into the concave portion of the L-shaped packing 71 having a rectangular ring shape, and is sandwiched between the end face of the upper film forming chamber wall 22 and the lip retainer 72. It is retained by inserting. The tip of the lip 7 is 480 mm on one side
Is a square. The L-shaped packing 71 and the lip retainer 72 are fixed to the end surface of the wall 22 by screws, so that the lip 7 can be easily attached and detached. The lip 7 is desirably divided into four parts for each side of the rectangular wall 22. . When the film forming chamber is opened, the lip 7 is inclined 45 to 60 degrees outward to the surface of the flexible substrate 1 and protrudes about 5 mm below the lower end of the L-shaped packing 71. The edge of the lip retainer 72 is chamfered, for example, by 30 °. When the wall body 22 starts to descend in the direction of the arrow 51 together with the housing 28 by the actuator 41, the tip of the lip 7 comes into contact with the substrate indicated by the dashed line, and further pushes the substrate 1 to form the end plates 23, 24 on the top plate 27. Reach on the surface. When the wall 22 descends in the direction of the arrow 53 as it is, the tip of the lip 7 slides outwardly in parallel with the surfaces of the end plates 23 and 24 and is deformed. The stroke of this lateral deformation is 4 mm. Since the edge of the lip retainer 72 is chamfered, the end of the deformed lip 7 can escape to this chamfer. At that time, friction occurs between the tip of the lip 7 and the substrate 1 on the cross sections 23 and 24, and the substrate 1 is pulled outward in the direction of the arrow 54. As shown in FIG. The end plates 23 and 24 are slid on the surface in the radial direction of an arrow 54 extending outward from the center, and wrinkles are extended. Then, as the descent continues, the L-shaped packing 71 moves the lower substrate 1 to the sealing material 5 and the end plate 2.
By pressing against the substrates 3 and 24, the space enclosed by the film formation space 6 below the substrate 1 and the wall 22 above the substrate 1 is vacuum sealed. FIG. 8 shows the film thickness distribution in the direction perpendicular to the transport direction of the a-Si film subsequently formed on the substrate 1 by a line 81 when the apparatus according to the embodiment of the present invention having the lip 7 is used. , Line 82 illustrates the use of a conventional device without a lip. When no lip is provided, it can be seen that the film thickness changes corresponding to the wrinkles described above. On the other hand, the a-Si
It was found that the film thickness distribution became almost uniform. The wrinkle height was estimated to be 3 to 5 mm from the film thickness distribution without the lip. Wrinkle cycle is about 80mm
Therefore, ideally, if the film substrate 1 is extended about 1/200 in the horizontal direction, it is considered that wrinkles will be extended. Therefore, as for the stroke of the tip of the lip 7 in the lateral direction, the effect starts to be seen if it is about 1/400 of the length of one side of the lip.
It is considered that a sufficient effect can be obtained if the ratio is / 200 or more. Further, the actuator 41 causes the ground electrode 32
Is lowered in the direction of arrow 55 shown in FIG. 9, and the substrate 1 is forcibly pulled in the direction of arrow 56 to further extend the wrinkles. At this time, it is effective that the depth d into which the ground electrode 32 is pushed into the substrate is 2.0 to 2.5 mm.

In the above-mentioned embodiment of the present invention, the upper film forming chamber can be evacuated, but only the lower film forming chamber accommodating the high voltage electrode is evacuated. Can also be implemented.

[0012]

According to the present invention, if a flexible substrate is formed by radially sliding the outer periphery of the film-forming surface on the end surface around the opening of the film-forming chamber wall to expand wrinkles, Since the formed film thickness was made uniform and the film pattern did not shift, the characteristics of the manufactured thin film photoelectric conversion element did not deteriorate. Then, the wrinkles could be easily stretched by using the inclined elastic lip provided on the end face of the wall facing the film forming chamber wall. In addition, by using an L-shaped packing material to hold the lip on the end face of the wall, it is possible to maintain a vacuum in a space in contact with both surfaces of the substrate with a small sealing area, and to provide a case in which a through hole is clear in the substrate. The equipment can be made more compact. Further, by using a method such as using a counter electrode as a pressing body,
By pushing the substrate into the film formation space, the effect of wrinkle expansion can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a film forming apparatus for manufacturing a thin film photoelectric conversion element according to an embodiment of the present invention when the film forming chamber is opened.

FIGS. 2A and 2B are cross-sectional views of a conventional film forming apparatus for manufacturing a thin film photoelectric conversion element, in which FIG.

FIG. 3 is a cross-sectional view of a substrate double-sided sealing structure of a conventional film forming apparatus.

FIG. 4 is a plan view of a seal structure on a top plate of a lower film formation chamber of the apparatus of FIG. 1;

FIG. 5 is a bottom view of an upper film forming chamber wall of the apparatus of FIG. 1;

FIG. 6 is a cross-sectional view of the seal structure of the apparatus of FIG. 1 when the film forming chamber is opened.

FIG. 7 is a sectional view of the sealing structure of the apparatus of FIG. 1 when the film forming chamber is sealed according to an embodiment of the present invention.

FIG. 8 is a film thickness distribution diagram of an a-Si film formed by a film forming apparatus according to an embodiment of the present invention and a conventional film forming apparatus.

9 is a cross-sectional view of the sealing structure of the apparatus of FIG. 1 when the film forming chamber is sealed according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible substrate 21 Lower film forming chamber wall 22 Upper film forming chamber wall 27 Top plate 28 Housing 29, 43 Moving plate 30 Vertical drive guide 31 High voltage electrode 32 Ground electrode 41, 44 Actuator 6 Film forming space 61 Vacuum Exhaust pipe 7 Lip 71 L-shaped packing 72 Lip holder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/04-31/078 H01L 21/205

Claims (13)

(57) [Claims] 1. A flexible substrate is brought into close contact with an end surface around an opening of a box-shaped film forming chamber wall, and a film forming space surrounded by the wall and the substrate is evacuated and housed in this space. In a method of manufacturing a thin-film photoelectric conversion element in which a voltage is applied to an electrode to form a thin film on a substrate, a substrate is formed by radially sliding an outer periphery of a deposition surface of a substrate on an end surface around an opening of a wall of a deposition chamber. A method of manufacturing a thin film photoelectric conversion element in which a film is formed after stretching wrinkles, wherein the tip of an elastic lip is pressed against the outer periphery of a film-forming surface of a substrate, and this tip is moved outward with the substrate by frictional force. Wherein the outer periphery of the deposition surface of the substrate is radially slid on the end surface around the opening of the wall of the deposition chamber. 2. The method of manufacturing a thin-film photoelectric conversion device according to claim 1, wherein the sliding distance of the tip of the lip is at least 1/400 of the distance between opposing sides of the lip in the sliding direction. 3. The method for manufacturing a thin-film photoelectric conversion element according to claim 1, wherein wrinkles of the substrate are extended by simultaneously using means for pressing the substrate toward the electrode by a pressing body located on the side opposite to the electrode. 4. The method for manufacturing a thin film photoelectric conversion device according to claim 3, wherein the substrate is pressed until the substrate surface enters a depth of 2.0 to 2.5 mm inward from the opening surface of the film forming chamber wall. 5. The method for manufacturing a thin-film photoelectric conversion element according to claim 3, wherein an opposing electrode of the electrode housed in the film-forming space is used as the pressing body. 6. A flexible substrate is brought into close contact with an end surface around an opening of a box-shaped film forming chamber wall, and a film forming space surrounded by the wall and the substrate is evacuated and housed in this space. In a method of manufacturing a thin-film photoelectric conversion element in which a voltage is applied to an electrode to form a thin film on a substrate, a substrate is formed by radially sliding an outer periphery of a deposition surface of a substrate on an end surface around an opening of a wall of a deposition chamber. A method for manufacturing a thin film photoelectric conversion element for forming a film after stretching wrinkles, wherein the wrinkles of the substrate are stretched together with a means for pressing the substrate toward the electrode side by a pressing body located on the side opposite to the electrode. A method for manufacturing a thin-film photoelectric conversion element, wherein an electrode opposite to an electrode housed in a film-forming space is used as the pressing body. 7. The method for manufacturing a thin film photoelectric conversion element according to claim 6, wherein the substrate is pressed until the substrate surface enters a depth of 2.0 to 2.5 mm inward from the opening surface of the film forming chamber wall. 8. A film-forming chamber surrounding the film-forming space and having an opening facing the opening of the box-shaped wall of the film-forming chamber in which an electrode to which a voltage is applied is accommodated, and being drivable in a direction toward the film-forming chamber wall. The end face of the second box-shaped wall is provided with an elastic lip-shaped body inclined outwardly with respect to the surface of the flexible substrate which is in close contact with the opening side of the wall of the film forming chamber. A film forming apparatus used in the method for manufacturing a thin-film photoelectric conversion element according to claim 1. 9. An inclination angle of the lip-like body with respect to the substrate surface is 45-6.
The film forming apparatus according to claim 8, wherein the angle is 0 °. 10. The method according to claim 8, wherein the second wall is rectangular, and the lip is divided into four parts parallel to each of the sides parallel and perpendicular to the longitudinal direction of the rectangular substrate. Film forming equipment. 11. The lip-shaped body is held on the end face of the second wall body by sandwiching a base between the packing material and the holding material having an L-shaped cross section fixed to the end face, respectively. The film forming apparatus according to any one of claims 10 to 13. 12. The film forming apparatus according to claim 11, wherein an elastic O-ring is provided on the end surface of the film forming chamber wall, facing the packing material on the end surface of the second wall. 13. A film-forming chamber surrounding the film-forming space and having an opening facing the opening of the box-shaped wall of the film-forming chamber in which an electrode to which a voltage is applied is accommodated, and being drivable in a direction toward the film-forming chamber wall. 6. The thin-film photoelectric conversion element according to claim 5, wherein the counter electrode accommodated in the second box-shaped wall body can be driven from the opening surface of the wall body of the film forming chamber to the inside while pressing the substrate on the surface. A film forming apparatus used in the method for manufacturing a semiconductor device.