JP2002212744A - Device for manufacturing thin film semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for manufacturing thin film semiconductors in which the attachment of reaction products to the portions other than the discharge space of a reaction chamber is prevented, removal and cleaning of the attached reaction products to a high-frequency electrode and an earthed electrode are facilitated to improve the maintainability, and the generation of abnormal electric discharge is prevented by the stabilization of the ground potential. SOLUTION: The inside of a vacuum tank 1 is divided into a reaction chamber 11 including a part of a drum roll 80, a high-frequency electrode 70, and a ground shield 72; and a non-reaction chamber 12 including the other part of the drum roll and a film substrate carrying means. A sealing means 9 for suppressing the flow of reaction gases is provided in a space located between the reaction chamber and the non-reaction chamber, and at the same time, between the above drum roll and the vacuum tank inner wall. A gas feeding means 13 and a gas exhaust means 16 communicating with the reaction chamber are provided. Furthermore, an auxiliary gas feeding means 17 for preventing the inflow of the reaction gases to the non-reaction chamber by pressurization is provided in the non-reaction chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus for forming a thin film such as amorphous silicon or microcrystalline silicon germanium on a film substrate to form a thin film semiconductor such as a thin film photoelectric conversion element or a thin film transistor.

[0002]

2. Description of the Related Art At present, research and development of clean energy are being promoted from the standpoint of environmental protection. Above all, solar cells are attracting attention because of their infinite resources (solar rays) and no pollution.

A typical example of a solar cell (photoelectric conversion device) in which a plurality of solar cell elements formed on the same substrate are connected in series is a thin film solar cell.

[0004] Thin-film solar cells are considered to be the mainstream of solar cells in the future because of their thinness, light weight, low manufacturing cost, and easy area enlargement. Demand is expanding for business use and general residential use, which are used for such purposes.

[0005] Conventional thin-film solar cells generally use a glass substrate. In recent years, research and development of a flexible solar cell using a plastic film in light of weight, workability, and mass productivity have been promoted and put into practical use. Further, a device using a film substrate insulated from a flexible metal material has been developed. Taking advantage of this flexibility, mass production has become possible by roll-to-roll or stepping roll manufacturing methods.

As the thin-film semiconductor for the thin-film solar cell, amorphous silicon (a-Si), which is a silicon-based non-single-crystal thin film, is used from the viewpoint of manufacturing cost, and the thin film is formed by plasma discharge. A thin film semiconductor device in which an alloy film such as the amorphous silicon (a-Si) or amorphous silicon germanium (a-SiGe) is formed by plasma discharge has a larger area, lower temperature, and lower cost than a single crystal silicon device. Therefore, application to thin-film transistors (TFTs) for displays, etc., in addition to large-area thin-film solar cells for electric power, is also expected.

The thin film formed by the plasma discharge is formed by, for example, the following apparatus. FIG.
1 shows an example of a schematic structure of a film forming chamber when an a-Si thin film solar cell is formed by plasma discharge.
An example of the structure described in Japanese Patent No. 50431 is shown. FIG.
(A) and (b) are schematic cross-sectional views when the film forming chamber is opened and sealed, respectively.

As shown in FIG. 4 (a), a box-shaped lower film-forming section chamber wall 34 and an upper film-forming section chamber wall 35 are arranged oppositely above and below a flexible substrate 10 which is intermittently conveyed. When the film forming chamber is sealed, an independent processing space including the lower film forming section chamber and the upper film forming section chamber is formed. In this example, the lower film forming unit chamber includes a high-frequency electrode 31 connected to a power supply 40, and the upper film forming unit room includes a ground electrode 32 having a built-in heater 33.

At the time of film formation, as shown in FIG. 4 (b), the upper film formation section chamber wall 35 descends, and the ground electrode 32 is
And is brought into contact with the seal member 50 attached to the opening-side end surface of the lower film-forming section chamber wall 34. As a result, an airtightly sealed film-forming space 60 communicating with the exhaust pipe 36 is formed from the lower film-forming section chamber wall 34 and the substrate 10. In the film forming chamber as described above, a high-frequency voltage is applied to the high-frequency electrode 31 to generate plasma in the film forming space 60, decompose the raw material gas introduced from an introduction pipe (not shown), and form a film on the substrate 10. Can be formed.

The source gas may be a kind of semiconductor thin film.
Generally, it depends on the gas mixture as follows.
Is used. That is, SiH_Four, GeH_Four, PH_Four, PH
_Three, B _TwoH₆For example, hydrogen is used as a dilution gas in these gases.
Mixed.

The thin-film semiconductor manufacturing apparatus shown in FIG.
The electrodes are flat, but sputtering or CVD
As a vapor deposition device, a device having a cylindrical electrode is also known.

FIG. 5 shows an example of the configuration of a thin-film semiconductor manufacturing apparatus proposed by the same applicant as the present invention for the purpose of facilitating removal and cleaning of CVD-generated deposits on a ground electrode (Japanese Patent Application No. 2000-2000). -252768).

The apparatus shown in FIG. 5 is a film fed from an unwinding roll 82 into a vacuum chamber 81 as a reaction chamber having a gas exhaust system 88 provided with a dry pump, a mechanic booster pump and a pressure control valve. Substrate 89
Susceptor roll 8 supported by heating roll 84
5, a reaction gas is supplied from a support portion of the opposing RF electrode (high-frequency electrode) 87, and the reaction gas is decomposed into plasma to form an amorphous silicon-based film or a microcrystalline film on a film substrate. Is wound up by a winding roll 83.

The heat of the heating roll 84 is transmitted to the susceptor roll 85 by radiation, conduction and convection. However, since the hydrogen of the diluent gas has a high thermal conductivity, the heat of the heating roll 84 is effectively transferred to the susceptor roll. Even if the heating roll has poor heat uniformity and its surface temperature distribution is ± 15 ° C., the surface temperature distribution of the susceptor roll can be kept within ± 10 ° C., and the heat uniformity can be improved.

According to the apparatus shown in FIG. 5, the adhered matter on the susceptor roll can be relatively easily cleaned using the space without the film substrate by rotating the susceptor roll. However, if the heating roll and the susceptor roll are detachable and the susceptor roll is configured to be detachable from the heating roll, cleaning becomes easier. The above-mentioned detachable structure is also disclosed in Japanese Patent Application No. 2000-252770.
No.

[0016]

However, the conventional manufacturing apparatus for forming a thin film semiconductor as described above has the following problems.

The conventional manufacturing apparatus shown in FIGS. 4 and 5 has a problem that a reaction product adheres to a portion of the reaction chamber other than the discharge space, and the reaction product is peeled off and re-adhered to the film substrate, thereby causing a thin film defect. there were.

The reaction product naturally adheres to the high-frequency electrode and the ground electrode or the susceptor roll that forms the discharge space. Must be removed and cleaned. However, in the conventional apparatus, it is not easy enough that the workability can be sufficiently satisfied, and there is a demand for an improvement in maintainability.

Furthermore, in particular, in the case of a cylindrical electrode, there is a problem that the ground potential (ground potential) is not stabilized, and abnormal discharge occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent reaction products from adhering to portions other than the discharge space of the reaction chamber, Easier removal and cleaning of reaction product deposits on the high-frequency electrode and the ground electrode to improve maintenance.
Another object of the present invention is to provide a thin-film semiconductor manufacturing apparatus which prevents abnormal discharge from occurring due to stabilization of a ground potential.

[0021]

In order to solve the above-mentioned problems, according to the present invention, there is provided a film substrate transporting means including a film substrate unwinding roll and a winding roll, and a film substrate. A drum roll as a ground electrode having a heating means, which is provided to form a thin film semiconductor on the surface of a film substrate by winding the portion, and a high-frequency electrode arranged in a notched concentric cylindrical shape facing the drum roll And a gas supply means for supplying a reaction gas corresponding to the thin film semiconductor into the vacuum chamber, and a gas exhaust means for exhausting the gas while controlling the pressure inside the vacuum chamber. In the vacuum chamber,
A reaction chamber for forming a thin-film semiconductor including a part of the drum roll and a high-frequency electrode, and a non-reaction chamber including the other part of the drum roll and a means for transporting a film substrate are divided into a reaction chamber. Between the non-reaction chamber and between the drum roll and the inner wall of the vacuum chamber, a sealing means for suppressing the flow of the reaction gas is provided, and the gas supply means and the gas exhaust means, The non-reaction chamber is provided in communication with the reaction chamber, and the non-reaction chamber is provided with an auxiliary gas supply means for preventing a reaction gas from flowing into the non-reaction chamber by pressurization. Invention).

According to the above configuration, the flow of the reaction gas into the non-reaction chamber is suppressed, the reaction product does not adhere to the non-reaction chamber, and the problem of the thin film defect due to the adhesion to the non-reaction chamber can be solved.

Further, as an embodiment of the first aspect of the present invention, the following second to seventh aspects of the present invention are preferable. That is, in the invention of claim 1, the drum roll includes a cylindrical susceptor roll and a heating roll for winding a film substrate, and the susceptor roll is
It shall be detachably fixed to the heating roll via a spacer for maintaining a predetermined gap (the invention of claim 2). This facilitates maintenance of the susceptor roll as a ground electrode.

Further, in the invention according to claim 2, in order to maintain a ground potential of the susceptor roll, ground holding means for electrically connecting the susceptor roll and a grounded heating roll is provided with the susceptor roll. (Embodiment 3), the ground potential is stabilized, and occurrence of abnormal discharge can be suppressed.

Further, according to the third aspect of the present invention, the ground holding means includes an elastic member for absorbing mechanical stress or thermal stress (the fourth aspect of the present invention), so that a dimensional error between the members can be obtained. And the mechanical stress based on the difference in the coefficient of thermal expansion can be reduced, and the ground potential can be stabilized.

Further, in order to further stabilize the ground potential, in the invention according to any one of the first to fourth aspects, the high-frequency electrode is disposed on the side opposite to the drum roll. In addition, it is preferable to provide a notched concentric cylindrically arranged earth shield along the high-frequency electrode.

Further, from the viewpoint of facilitating maintenance of the high-frequency electrode, the invention of the following claim 6 is preferable. That is, in the manufacturing apparatus according to any one of claims 1 to 5, the non-reaction chamber is divided into three chambers, a drum roll chamber, an unwind roll chamber, and a take-up roll chamber. A seal gate means that can be hermetically sealed via a film substrate in a film substrate penetrating portion between the film chamber and the drum roll chamber and between the winding roll chamber and the drum roll chamber; The high-frequency electrode disposed on the side is airtightly sealed between the respective chambers via a film substrate by the seal gate means,
The high-frequency electrode is provided so as to be detachable from a vacuum chamber.

According to the above configuration, in addition to the ease of maintenance of the high-frequency electrode, the unwind roll chamber and the take-up roll chamber can be maintained in vacuum during the maintenance of the high-frequency electrode, which is preferable in maintaining the quality of the film substrate. ,
Evacuation time at the time of restart after maintenance is completed is reduced.

In the invention of claim 6, the seal gate means preferably has the same structure as the seal mechanism shown in FIG. 4, and the invention of claim 7 below is suitable. That is, in the manufacturing apparatus according to claim 6, the seal gate means is provided with a seat having a sealing material on one side of the film substrate, and sealing the film substrate on the other side, with the film substrate interposed therebetween. A member that can be pressed toward the material is provided.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 are schematic structural views of an embodiment of the apparatus for manufacturing a thin film semiconductor according to the present invention. 1 shows the overall configuration of the apparatus, FIG. 2 shows details of the sealing means, and FIG. 3 shows details of the drum roll.

The apparatus shown in FIG. 1 includes an unwinding roll 82 and a winding roll 83 for a film substrate 89 in a vacuum chamber 1.
Transport means for the film substrate including the auxiliary roll 7 and the touch roll 8; and a ground electrode having a heating means provided for winding a part of the film substrate 89 to form a thin film semiconductor on the surface of the film substrate. Drum roll 8 as
0, and a high-frequency electrode (RF electrode) 70 arranged in a notched concentric cylindrical shape facing the drum roll 80.
A gas supply unit 13 for supplying a reaction gas also serving as a support for the F electrode and a gas exhaust unit 16 are provided.

The inside of the vacuum chamber 1 includes a reaction chamber 11 containing a part of the drum roll 80 and the high-frequency electrode 70, and a non-reaction chamber 12 containing the other part of the drum roll 80 and a means for transporting the film substrate. Sealing means 9 shown in detail in FIG. 2 is provided between the reaction chamber and the non-reaction chamber between the drum roll and the inner wall of the vacuum chamber so as to suppress the flow of the reaction gas. It is composed of

Further, the gas supply means 13 and the gas exhaust means 16 are provided in communication with the reaction chamber 11, and the non-reaction chamber is pressurized to prevent the reaction gas from flowing into the non-reaction chamber. Auxiliary gas supply means 17 is provided.

In the above configuration, the film substrate 89 sent out from the unwinding roll 82 is wound around the heated drum roll 80, and the opposed RF electrode (high-frequency electrode) 7
The reaction gas is supplied from the gas supply means 13 which also serves as a support portion of the substrate, and the reaction gas is decomposed into plasma to form an amorphous silicon-based film or a microcrystalline film on a film substrate. It is configured to wind up.

In FIG. 1, reference numeral 72 denotes an earth shield, which stabilizes the ground potential. Further, the non-reaction chamber 12 is divided into three chambers: a drum roll chamber 12a, an unwind roll chamber 12b, and a take-up roll chamber 12c. A seal gate means 6 that can be hermetically sealed via a film substrate 89 is provided in the film substrate penetrating portion between the take-up roll chamber 12c and the drum roll chamber 12a. Furthermore, the high-frequency electrode 70
Is a high-frequency electrode 7 in a state in which the chambers are hermetically sealed via a film substrate by the seal gate means 6.
The lid 19 is fastened and fixed to the bottom surface of the reaction chamber via a sealing device 18 so that the high-frequency electrode 70 can be detached from the vacuum chamber 1 so that the high-frequency electrode 70 can be detached. Assembled. 1
Reference numeral 4 denotes a lifting device for disassembly and assembly. The structure of the seal gate means 6 is as described in the above-mentioned claim 7, and FIG. 1 shows only the seat 25 having a sealing material on one side with the film substrate interposed between the film substrate penetrating portion. Is shown.

Next, referring to FIG. 2, the sealing means 9 provided between the reaction chamber and the non-reaction chamber will be described in more detail. 2A is a partial cross-sectional view as viewed from the same direction as FIG. 1, and FIG. 2B is a top view of FIG. 2A.

The sealing means 9 comprises a roll shaft end seal 21 and a roll shaft direction seal 22, as shown in FIG. There are gaps between the drum roll 80 and the inner wall of the vacuum chamber 1 between both ends in the axial direction of the drum roll 80 and the inner wall of the vacuum chamber, and between both left and right sides in the axial direction and the inner wall of the vacuum chamber. Roll shaft end seal 2 according to the gap
1 and a roll axial seal 22 are provided.

The roll shaft end seal 21 is attached to the drum roll 8
In order not to hinder the rotation of the rotation axis 0 and to prevent the roll axial seal 22 from damaging the substrate film 89, the sealing material is softly urged by the elastic body from the inner wall of the vacuum chamber. The configuration is as follows. Substrate film 8
Although complete airtightness cannot be expected in order to safely transport the fuel cell 9 without damaging it, for example, hydrogen gas is introduced from the auxiliary gas supply means 17 so that the pressure on the non-reaction chamber side is increased to the pressure on the reaction chamber side. By making them equal or higher, it is possible to prevent the reaction gas from leaking from the reaction chamber side to the non-reaction chamber side.

Next, FIG. 3 shows an embodiment of the structure of the drum roll. The drum roll shown in FIG.
Similarly to the configuration described in Japanese Patent Application Publication No. 000-252770, the susceptor roll 8 includes a cylindrical susceptor roll 85 and a heating roll 84 for winding a film substrate.
5 is detachably fixed to the heating roll 84 via a pin-shaped holding spacer 91 for holding a predetermined gap.

In order to maintain the ground potential of the susceptor roll 85, a plurality of ground holding means 92 for electrically connecting the susceptor roll 85 and the heating roll 84 to be grounded are provided. It is provided between the roll 84. The material of the ground holding means 92 is aluminum or stainless steel.

The holding spacer 91 includes a heating roll 84
And a minute adjustment mechanism (not shown) for adjusting the gap with a screw, a spring, or the like, using the as a fulcrum. The number of the holding spacers 91 depends on the diameter and length of the roll.

The holding spacer may be provided at the end of the heating roll 84. When the material of the susceptor roll 85 and the material of the heating roll 84 are different, and the temperature of the heating roll becomes high and the occurrence of thermal strain becomes a problem, the end holding spacers use a spring or a heat-resistant cushion material to reduce the thermal stress. It can be configured to absorb. Further, it is desirable that the ground holding means 93 is also provided with an elastic member for absorbing mechanical stress or thermal stress. Also,
In FIG. 3, reference numeral 93 denotes a temperature sensor for detecting the temperature of the susceptor roll, which is provided as needed, and can be provided at a position which does not hinder winding of the substrate.

[0044]

As described above, according to the present invention, a reaction chamber for forming a thin film semiconductor including a part of a drum roll and a high-frequency electrode, the other part of the drum roll and a film are formed in the vacuum chamber. A sealing means for separating a non-reaction chamber including a substrate transfer means and a non-reaction chamber between the reaction chamber and the non-reaction chamber and between the drum roll and the inner wall of the vacuum chamber for suppressing the flow of a reaction gas; And a gas supply means and a gas exhaust means are provided in communication with the reaction chamber, and an auxiliary for preventing the reaction gas from flowing into the non-reaction chamber by pressurizing the non-reaction chamber. By providing the gas supply means, the flow of the reaction gas to the non-reaction chamber is suppressed, the reaction product does not adhere to the non-reaction chamber,
The problem of thin film defects due to non-reaction chamber deposits can be solved.

Further, the high-frequency electrode is provided with an earth shield which is cut out along the high-frequency electrode and arranged in a concentric cylindrical shape on the side opposite to the drum roll, so that the drum roll is further connected to a susceptor roll and a heating roll. In this case, the ground holding means is provided between the susceptor roll and the heating roll, so that the problem of discharge generation can be solved by stabilizing the ground potential.

Further, the non-reaction chamber is divided into three chambers of a drum roll chamber, a take-up roll chamber, and a take-up roll chamber, between the take-up roll chamber and the drum roll chamber, and the take-up roll chamber. A seal gate means that can be hermetically sealed via the film substrate is provided in the film substrate penetrating portion between the and the drum roll chamber, and a high-frequency electrode provided on the reaction chamber side of the vacuum chamber is provided with a seal gate means. When the high-frequency electrodes are detachably provided from the vacuum chamber in a state where the respective chambers are hermetically sealed via a film substrate, the maintainability of the high-frequency electrodes is improved.

[Brief description of the drawings]

FIG. 1 is a schematic overall view of a thin-film semiconductor manufacturing apparatus according to an embodiment of the present invention;

2 is a configuration diagram of a sealing means between a reaction chamber and a non-reaction chamber of the manufacturing apparatus shown in FIG.

FIG. 3 is a configuration diagram of a drum roll of the manufacturing apparatus shown in FIG.

FIG. 4 is a diagram showing an example of a schematic structure of a conventional film forming chamber.

FIG. 5 is a diagram showing an example of a conventional film forming apparatus different from FIG.

[Explanation of symbols]

1: vacuum chamber, 6: seal gate means, 9: seal means,
11: reaction chamber, 12: non-reaction chamber, 12a: drum roll chamber, 12b: unwind roll chamber, 12c: take-up roll chamber, 13: gas supply means, 16: gas exhaust means, 17:
Auxiliary gas supply means, 25: seat, 70: high frequency electrode, 7
2: earth shield, 80: drum roll, 82: unwind roll, 83: take-up roll, 84: heating roll, 8
5: susceptor roll, 89: film substrate, 91: holding spacer, 92: ground holding means.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4K030 BA30 CA07 CA12 EA11 FA03 GA02 GA14 KA10 KA23 KA30 KA41 LA15 LA16 5F045 AA08 AB03 AB04 BB10 BB14 CA13 CA15 DP22 EB02 EB03 EE14 EH04 EH06 EH12 EH19 CA25A15A22

Claims (7)

[Claims] 1. A film substrate transporting means including a film substrate unwinding roll and a winding roll inside a vacuum chamber;
A drum roll serving as a ground electrode having a heating means provided for winding a part of the film substrate to form a thin film semiconductor on the surface of the film substrate; and a notched concentric cylindrical shape facing the drum roll. A thin film having gas supply means for supplying a reaction gas corresponding to the thin film semiconductor into the vacuum chamber, and gas exhaust means for exhausting the gas while controlling the pressure inside the vacuum chamber. In the semiconductor manufacturing apparatus, the inside of the vacuum chamber includes a reaction chamber for forming a thin film semiconductor including a part of the drum roll and a high-frequency electrode, and a transport unit for transporting a film substrate and another part of the drum roll. A non-reaction chamber, and sealing means for suppressing the flow of the reaction gas is provided between the reaction chamber and the non-reaction chamber and between the drum roll and the inner wall of the vacuum chamber. And, the gas supply means and the gas exhaust means are provided in communication with the reaction chamber, and further, the non-reaction chamber is provided with a pressure for preventing the reaction gas from flowing into the non-reaction chamber. An apparatus for manufacturing a thin film semiconductor, comprising an auxiliary gas supply means. 2. The manufacturing apparatus according to claim 1, wherein the drum roll includes a cylindrical susceptor roll for winding a film substrate and a heating roll, and the susceptor roll maintains a predetermined gap. A thin-film semiconductor manufacturing apparatus, which is detachably fixed to a heating roll via a spacer for the purpose. 3. The manufacturing apparatus according to claim 2, wherein said ground holding means for electrically connecting a susceptor roll and a grounded heating roll is electrically connected to hold the ground potential of said susceptor roll. An apparatus for manufacturing a thin film semiconductor, provided between a susceptor roll and a heating roll. 4. The apparatus according to claim 3, wherein said ground holding means includes an elastic member for absorbing mechanical stress or thermal stress. 5. The manufacturing apparatus according to claim 1, wherein the high-frequency electrode includes a ground shield, which is notched and arranged in a concentric cylindrical shape along the high-frequency electrode, on a side opposite to the drum roll. An apparatus for manufacturing a thin film semiconductor, comprising: 6. The manufacturing apparatus according to claim 1, wherein the non-reaction chamber is divided into three chambers: a drum roll chamber, an unwind roll chamber, and a take-up roll chamber. A seal gate means that can be hermetically sealed via a film substrate is provided at a portion between the roll chamber and the drum roll chamber and between the take-up roll chamber and the drum roll chamber, and further, the vacuum chamber The high-frequency electrode provided on the reaction chamber side of the above-mentioned is configured such that the high-frequency electrode is detachably provided from a vacuum chamber in a state where the respective chambers are hermetically sealed via a film substrate by the seal gate means. An apparatus for manufacturing a thin film semiconductor, comprising: 7. The manufacturing apparatus according to claim 6, wherein the seal gate means is provided with a seat having a sealing material on one side with the film substrate interposed between the film substrate penetrating portion and the film on the other side. An apparatus for manufacturing a thin film semiconductor, comprising a member capable of pressing a substrate toward a sealing material.