JP3314711B2 - Thin film manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film manufacturing apparatus for forming a thin film of a semiconductor or metal on a flexible substrate by a stepping roll method.

[0002]

2. Description of the Related Art A method of manufacturing a thin film solar cell mainly composed of amorphous silicon (hereinafter referred to as a-Si) by forming it on a flexible substrate made of a polymer material or a metal such as stainless steel has been proposed. 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.

When a film is formed by plasma CVD in the stepping roll 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 started, a discharge is started, a discharge is ended, and a source gas is stopped. The operation of degassing and opening the film forming chamber is repeated. As a prior art relating to a stepping roll type thin film manufacturing apparatus, Japanese Patent Application Laid-Open No. 6-291
349, JP-A-7-6953, JP-A-8-
There is 250431 gazette.

This thin film manufacturing apparatus of the stepping roll type is superior in the following points to a roll-to-roll thin film manufacturing apparatus in which conveyance is not stopped even during normal film formation. (1) Since the film formation chamber is closed during film formation, there is no gas mutual diffusion with the adjacent film formation chamber. (2) There is no need to provide a gas curtain between adjacent film forming chambers to prevent gas diffusion, and the thin film manufacturing apparatus is compact.

[0005] In particular, a description will be given of a conventional stepping roll device pursuing compactness and improvement in productivity.
FIG. 6 is a cross-sectional view taken along a direction perpendicular to the substrate and along the substrate transport direction when a film forming chamber in a conventional stepping roll type thin film manufacturing apparatus is opened. This is an apparatus that can simultaneously form films on two film substrates. A ground electrode 2 also serving as a heater and a high-frequency electrode 3 are arranged to face each other with the two substrates 1 opposed to each other interposed therebetween. A number of small holes are formed in the surface of the high-frequency electrode 3 on the substrate 1 side, and the gas introduced from the gas introduction pipe 6 is uniformly blown out. Thin arrows indicate the direction of gas flow. The deposition chamber partition 4 of the deposition chamber in which the high-frequency electrode 3 is housed together with the ground electrode 2 has a flat portion 4a, a side wall portion 4b at the periphery thereof, and the ground electrode 2
4f. A part of the side wall 4b is an insulating frame 4c. A sealing material 4s is fitted to the flange 4f. When the film forming chamber is closed, the ground electrode 3 is driven by the arm 8a of the driving device 8 in the direction of the thick arrow V, and presses the substrate 1 against the seal portion 4c to make the film forming chamber a closed space. The deposition chamber is the substrate 1
The discharge space between (or the ground electrode 2) and the high-frequency electrode 3 occupies 50% or more of the whole, and is very compact. Two film forming chambers located at the same position in the transport direction are connected to one exhaust pipe 7.
Communication. The film forming chamber is surrounded by a common chamber wall 5 together with other film forming chambers and a transfer device (not shown), housed in the common room, and isolated from the atmosphere.

The flat portion 4a of the partition 4 of the film forming chamber is
Are maintained at the same potential, but the discharge from the flat portion 4a can be suppressed by keeping the pressure of the common chamber during film formation at 0.1 Pa or less. However, since the pressure inside the exhaust pipe 7 is maintained at a pressure required for film formation at 10 to 100 Pa, the exhaust pipe 7 is made of an insulating material to avoid discharge.
The distance between two high-frequency electrodes 2 is 10 cm or more.

As an arrangement of the high-frequency electrodes, a configuration in which one high-frequency electrode is formed at the center and discharge is performed on both surfaces thereof is also conceivable. However, in order to make the film thickness on both sides of the high-frequency electrode uniform, it is necessary to control the discharge on both sides independently, but this is difficult with one high-frequency electrode. A method in which discharge is independently controlled by electrodes is adopted.

[0008]

The above-described thin film manufacturing apparatus of the stepping roll type has the following problems. In order to prevent discharge in the exhaust pipe, it is necessary to separate the high-frequency electrodes by 10 cm or more, and the width of the common chamber, that is, the entire width of the thin film manufacturing apparatus is increased. Therefore, the volume of the common chamber is large, and the exhaust device that exhausts the common chamber becomes large. Therefore, a large installation area is required in the clean room, and the apparatus becomes expensive, which increases the film formation cost.

A heavy aluminum cast heater is used for the ground electrode also serving as a heater in order to improve heat uniformity. For this reason, the drive system of the ground electrode becomes large, the equipment cost increases, and the film formation cost increases. An object of the present invention is to provide a thin film manufacturing apparatus of a stepping roll type which is lighter than the conventional one and has a small installation area.

[0010]

In order to achieve the above object, at least a ground electrode, two high-frequency electrodes disposed opposite to both surfaces thereof and for blowing a raw material gas from the surface, and these high-frequency electrodes And two or more film-forming chamber partitions for forming a closed film-forming chamber whose opening is in close contact with the ground electrode with the substrate interposed therebetween during film formation, and one or more pairs of the film-forming chambers. In a stepping roll type thin film manufacturing apparatus comprising a common chamber in which electrodes are fixed, and using a discharge between a ground electrode and a high-frequency electrode, a film forming chamber partition is provided with an exhaust pipe of a source gas. Is provided,
The exhaust pipe and the feed pipe for the source gas provided in the high-frequency electrode pass through a portion of the common chamber wall parallel to the high-frequency electrode.

It is preferable that portions of the exhaust pipe and the introduction pipe penetrating the common chamber wall are made of an insulator, and discharge in these pipes is prevented. A seal is provided on a portion of the film forming chamber partition wall that is in close contact with the ground electrode, and the pressure of the common chamber is set to 0 during film formation so that discharge does not occur in the common chamber.
It is desirable that the pressure can be maintained at 1 Pa or less or atmospheric pressure.

Preferably, the high-frequency electrode is fixed to the partition wall of the film forming chamber, and is opened and closed by a driving device provided outside the common chamber simultaneously with the partition wall of the film forming chamber. The film forming chamber partition is divided into a plane portion and a side wall portion, the high-frequency electrode is fixed to the common chamber wall together with the flat portion of the film forming chamber partition, and the side wall portion is provided outside the common chamber. The introduction pipe and the discharge pipe attached to the side wall are preferably provided with a bellows between the walls of the common chamber to keep the airtightness of the common chamber.

It is preferable that the flat part and the side wall part of the partition wall of the film forming chamber are connected by bellows to keep the airtightness of the film forming chamber.
It is preferable that a seal portion is provided between the flat portion and the side wall portion of the film forming chamber partition wall, and the flat portion and the side wall portion are in close contact with each other with the seal portion interposed therebetween, so that the airtightness of the film forming chamber is maintained. The side wall portion of the film forming chamber partition is divided into a fixed portion and a movable portion integrated with a plane portion, and the high-frequency electrode is fixed to the common chamber wall together with the fixed portion, and the fixed portion and the movable portion A bellows made of an insulative and flexible polymer film is provided therebetween to keep the airtightness of the film forming chamber, and the movable portion is preferably opened and closed by a driving device provided outside the common chamber.

The sum of the distances from the end of the plane part of the film forming chamber partition wall which contacts the exhaust pipe to the inner surface of the exhaust pipe to the end of the common chamber which contacts the exhaust pipe is 30 mm.
It is good if it is above. In order to realize the sum of the above-mentioned distances, the exhaust pipe is thick, or a hole in the common chamber wall through which the exhaust pipe penetrates is larger than the outer shape of the exhaust pipe, and the exhaust pipe is made of an insulator. The wall of the common chamber, which is supported by a supporting member or through which the exhaust pipe penetrates, may protrude outside the wall of the common chamber on the outer periphery.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a cross-sectional view along a substrate transfer direction when a film forming chamber of a thin film manufacturing apparatus according to an embodiment of the present invention is opened. The ground electrode 2 also serving as a heater is fixed substantially at the center of the common chamber, and the high-frequency electrodes 3 are arranged on both sides thereof. The high-frequency electrode 3 has the same shape as the conventional one, and a gas is introduced from a gas introduction pipe 6 and is uniformly blown out from a large number of small holes to a film formation region. Gas flow is indicated by thin arrows. The two film substrates 1 are transported to both sides of the ground electrode 2. Deposition chamber wall 4
Is composed of a plane portion 4a, a side wall portion 4b, an insulating frame 4c, and a flange 4f. An insulating gas exhaust pipe 7 is attached to the flat portion 4a, and the gas exhaust pipe 7 penetrates the common chamber wall 5 and protrudes outside the common chamber. A bellows B1 is connected between the flange 7f attached to the end of the gas exhaust pipe 7 and the common chamber wall 5 to keep the airtightness between the common chamber and the atmosphere. The length of the gas exhaust pipe 7 needs to be 10 cm or more so as not to cause a discharge inside the flat portion 4a or between the high-frequency electrode 2 and the common chamber wall 5. Gas exhaust pipe 7
May be singular or plural, but if singular, they are arranged symmetrically at the center of the plane portion 4a of each film forming chamber wall, and if plural, they are arranged symmetrically at the center. This arrangement of the exhaust pipe makes it possible to reduce the thickness of the common chamber by substantially the sum of the exhaust pipe length and the thickness of the ground electrode. Although not shown here, a stainless steel bellows is used for connection to the pressure controller and the evacuation system.

The flat portion 4a may be made of either a metal or an insulator. In the case of a metal, it is necessary that the flat portion 4a is brought into contact with a high-frequency electrode to maintain the same potential so that no discharge occurs. In the case of an insulator, it may be integrated with the insulating frame 4b or the gas exhaust pipe 7. For the gas exhaust pipe 7, an insulating material such as ceramic or heat-resistant fluororesin can be used.

The opening and closing of the film forming chamber wall 4 (in which the high-frequency electrode is also integrated) is performed by an arm 8 of a driving device 8 installed on the common chamber wall 5. In order to prevent discharge from occurring in the common chamber during film formation, it is necessary to maintain the pressure in the common chamber at 0.1 Pa or less. In addition to the ring, the film substrate itself, metal, ceramic, glass, or the like can be used.

According to this embodiment, the thin-film manufacturing apparatus is smaller in size than the conventional one, mainly because the width of the common chamber is narrower by one ground electrode, so that the weight is reduced to one, and the driving device is correspondingly lighter. As a result, the weight of the entire thin film manufacturing apparatus was reduced. Embodiment 2 FIG. 2 is a cross-sectional view along a substrate transport direction of a film forming chamber of a thin film manufacturing apparatus according to another embodiment of the present invention. The difference from the first embodiment is that the high-frequency electrode 3 and the flat part 4a are fixed to the common chamber wall 5 by the gas exhaust pipe 7, and the side wall part 4b of the film forming chamber partition is connected to the flat part 4a by the bellows B3. It can be moved. Since there are fewer movable parts than in the first embodiment, the force required for opening and closing the film forming chamber, that is, for driving the movable parts is smaller, and the driving device 8 can be made smaller. Also, the high-frequency electrode 3 is connected to the common chamber wall 5.
Since it is fixed, the generation of powder and flakes accompanying the movement of the high-frequency electrode 3 is eliminated, and there is the advantage that the adhesion to these films is smaller and the characteristic stability during mass production of solar cells is good. Third Embodiment FIG. 3 is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus according to another embodiment of the present invention, taken along a substrate transport direction. A seal 4t is used instead of the bellows B3 connecting the flat part 4a of the film forming chamber and the side wall part 4b of the film forming chamber in the second embodiment, and the film substrate 1 can be sealed with the seal S1 and simultaneously with the flat part 4a. It has become. It is also effective to replace a part of the film forming chamber side wall 4b with a bellows in order to ensure simultaneous sealing. As the seal 4t, similarly to the seal 4s, besides the fluororesin, the film substrate itself, metal, ceramic, glass, or the like can be used.

As in the case of the second embodiment, the installation area can be reduced by reducing the weight and the width. Fourth Embodiment FIG. 4 is a cross-sectional view of a thin film manufacturing apparatus according to another embodiment of the present invention, taken along a substrate transport direction of a film forming chamber. Deposition chamber side wall 4
The insulator frame 4c, which is a part of b, is not a rigid body such as glass or ceramic but a film 4g made of a heat-resistant and insulating material such as polyimide or aramid. The film 4g is stretched in the direction of the ground electrode, and the seal 4s is attached to the substrate 1
The film formation chamber can be closed by bringing the electrode into close contact with the ground electrode 2 through the electrode. That is, Example 2 was applied to film 4g.
It has the same function as the bellows B3 in FIG. In this embodiment, the weight of the movable portion is the smallest as compared with the other embodiments. For this reason, the drive system can be further reduced in size, and the installation area of the thin film manufacturing apparatus can be reduced, and as a result, the cost of the thin film manufacturing apparatus can be reduced. Example 5 The distance between the common wall and the partition of the film forming chamber was reduced as much as possible,
The thickness of the thin film manufacturing apparatus can be reduced. In this case, the sum of the distances from the end of the common wall in contact with the exhaust pipe to the end of the film forming chamber partition wall that contacts the exhaust pipe through the inside of the exhaust pipe is small, so that these ends are close to these ends in the exhaust pipe. Electric discharge may occur in the space. In order to prevent the powder generated by this discharge from adhering to the thin film, it is necessary to keep these ends apart. FIG. 5 is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus in which an end of a film forming chamber partition wall according to the present invention that is in contact with an exhaust pipe is kept away (a) when a thick exhaust pipe is used.
(B) shows a case where another insulating gas exhaust pipe supporting member is interposed, and (c) shows a case where a detour wall of the common chamber wall is provided.
For simplification of the drawing, only the film forming chamber on one side is shown. In each case, a thick exhaust pipe 7a is used, or a hole in a common chamber wall through which the exhaust pipe penetrates is made larger than the outer shape of the exhaust pipe.
The exhaust pipe is supported by another insulating gas exhaust pipe support member 7b such as ceramics or heat-resistant resin, or the wall of the common chamber where the exhaust pipe 7 penetrates is located outside the common chamber wall of the outer peripheral edge. By projecting, detour wall 5 of the common room wall
a is formed, and so on. In each case,
It is apparent that the sum of the distances from the end of the common chamber wall contacting the exhaust pipe to the inner surface of the exhaust pipe and the end of the film forming chamber partition contacting the exhaust pipe is large. If the sum of the distances is less than 30 mm, discharge may occur inside the exhaust pipe 7.

The thin-film manufacturing apparatus of the first to fourth embodiments, in which a discharge prevention measure in the exhaust pipe is applied, has a small installation area and is light in weight so that it is suitable for installation in a clean room. became.

[0021]

According to the present invention, a ground electrode, two high-frequency electrodes disposed opposite to both surfaces thereof, and blowing out a source gas from the surface, respectively surround these high-frequency electrodes,
At the time of film formation, two film-forming chamber partition walls forming an open film-forming chamber in which an opening is in close contact with a ground electrode with a substrate interposed therebetween, and one or a plurality of film-forming chamber pairs are incorporated therein, and the ground electrode is fixed. In a stepping roll type thin film manufacturing apparatus comprising a common chamber having a common chamber and using a discharge between a ground electrode and a high-frequency electrode, an exhaust pipe for a source gas is provided in the partition of the film forming chamber. Since the tube and the feed tube for the source gas provided in the high-frequency electrode penetrate through a portion of the common chamber wall parallel to the high-frequency electrode, the thin-film manufacturing apparatus is mainly provided with a common chamber only for one ground electrode. Is narrow and compact, the weight of the ground electrode is reduced to one, and the movable part is lighter because the ground electrode is removed from the movable part.
Correspondingly, the driving device became lighter, so that the weight of the entire thin film manufacturing apparatus was reduced.

As a result, thin-film solar cells can be manufactured on a flexible substrate with high productivity, which can contribute to cost reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus according to an embodiment of the present invention, taken along a substrate transport direction.

FIG. 2 is a cross-sectional view taken along a substrate transport direction of a film forming chamber of a thin film manufacturing apparatus according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus according to another embodiment of the present invention, taken along a substrate transport direction.

FIG. 4 is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus according to another embodiment of the present invention, taken along a substrate transport direction.

FIG. 5A is a cross-sectional view of a film forming chamber of a thin film manufacturing apparatus in which an end of a film forming chamber partition wall according to the present invention, which is in contact with an exhaust pipe, is kept away (a).
(B) shows the case where another insulating member is interposed, and (c) shows the case where the common chamber wall is bypassed.

FIG. 6 is a cross-sectional view taken along a substrate transport direction perpendicular to a substrate when a film forming chamber in a conventional stepping roll type thin film manufacturing apparatus is opened.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 film substrate 2 ground electrode 3 high-frequency electrode 4 film forming chamber partition 4 a flat surface 4 b side wall 4 c insulating frame 4 f flange 4 s seal 4 t seal 4 g insulating film 5 common chamber wall 5 a detour wall 6 gas introduction pipe 6 f flange 7 gas Exhaust pipe 7a Thick gas exhaust pipe 7b Gas exhaust pipe support member 7f Flange 8 Drive 8a Drive arm B1 Bellows B2 Bellows B3 Bellows V Opening / closing direction of film forming chamber

Claims (12)

(57) [Claims] 1. At least a ground electrode, two high-frequency electrodes disposed opposite to both surfaces thereof for blowing a raw material gas from the surface, each surrounding these high-frequency electrodes, and an opening sandwiching the substrate during film formation. And two film forming chamber partitions forming a closed film forming chamber in close contact with the ground electrode,
A stepping roll type thin film manufacturing apparatus comprising a plurality of built-in common chambers to which the ground electrode is fixed, wherein a film is formed by using a discharge between the ground electrode and the high-frequency electrode. Is provided with a source gas exhaust pipe, and the exhaust pipe and the source gas introduction pipe provided in the high-frequency electrode penetrate through a portion of the common chamber wall parallel to the high-frequency electrode. Thin film manufacturing equipment. 2. A thin film manufacturing apparatus according to claim 1, wherein portions of said exhaust pipe and said inlet pipe penetrating through said common chamber wall are made of an insulator, and discharge in these pipes is prevented. apparatus. 3. A seal is provided at a portion of the partition wall of the film forming chamber which is in close contact with the ground electrode, and a pressure in the common chamber is set to 0.1 Pa or less or an atmospheric pressure during film formation so that discharge does not occur in the common chamber. 2. The apparatus according to claim 1, wherein
2. The thin film manufacturing apparatus according to claim 1. 4. The apparatus according to claim 1, wherein the high-frequency electrode is fixed to the partition wall of the film forming chamber, and is opened and closed by a driving device provided outside the common chamber at the same time as the partition wall of the film forming chamber. Thin film manufacturing equipment. 5. The film forming chamber partition is divided into a flat portion and a side wall portion, and the high-frequency electrode is fixed to the common chamber wall together with the flat portion of the film forming chamber partition, and the side wall portion is outside the common chamber. 4. A bellows is provided between a common chamber wall of the introduction pipe and the discharge pipe which is opened and closed by a driving device provided and is attached to a side wall part, so that the airtightness of the common chamber is maintained. 2. The thin film manufacturing apparatus according to claim 1. 6. The thin film manufacturing apparatus according to claim 5, wherein the flat part and the side wall part of the film forming chamber partition are connected by a bellows to keep the film forming chamber airtight. 7. A seal portion is provided between the flat portion and the side wall portion of the film forming chamber partition wall, and the flat portion and the side wall portion are in close contact with each other with the seal portion interposed therebetween, thereby keeping the film forming chamber airtight. The thin film manufacturing apparatus according to claim 5, wherein: 8. A side wall of the film forming chamber partition is divided into a fixed portion and a movable portion integrated with a plane portion, and the high-frequency electrode is fixed to the common chamber wall together with the fixed portion.
A bellows made of an insulating and flexible polymer film is provided between the fixed part and the movable part to maintain the airtightness of the film forming chamber, and the movable part is opened and closed by a driving device provided outside the common chamber. The thin film manufacturing apparatus according to claim 1, wherein: 9. The sum of the distances from the end of the plane part of the film forming chamber partition wall in contact with the exhaust pipe to the inner surface of the exhaust pipe to the end of the common chamber in contact with the exhaust pipe is: 30mm
9. The apparatus for manufacturing a thin film according to claim 1, wherein: 10. The apparatus according to claim 9, wherein said exhaust pipe is thick. 11. The exhaust pipe according to claim 9, wherein a hole in the common chamber wall through which the exhaust pipe penetrates is larger than an outer shape of the exhaust pipe, and the exhaust pipe is supported by a support member made of an insulator. The thin film manufacturing apparatus according to the above. 12. The thin-film manufacturing apparatus according to claim 9, wherein the wall of the common chamber at a portion through which the exhaust pipe penetrates protrudes outward from the wall of the common chamber at an outer peripheral edge thereof.