JPH0579940U - Plasma CVD equipment - Google Patents

Abstract

(57) [Summary] [Purpose] A film having a uniform film thickness can be formed, and the film quality becomes more uniform. [Structure] A regular polygonal cylindrical body and an electrode plate are opposed to each other in the reaction chamber, and a plurality of flat plate-shaped substrates are arranged on each peripheral surface of the cylindrical body, and an amorphous silicon semiconductor layer is formed in the reaction chamber. A gas for use is introduced to rotate the cylindrical body, and a voltage is applied between the cylindrical body and the electrode plate or between the flat plate-shaped substrate and the electrode plate to generate plasma, which is simultaneously applied to the plurality of flat plate-shaped substrates. A plasma CVD apparatus characterized in that an amorphous silicon semiconductor layer is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a plasma CVD apparatus capable of simultaneously forming amorphous silicon semiconductor layers on a plurality of flat substrates.

[0002]

[Prior Art]

 In recent years, amorphous silicon-based semiconductor layers have been used in various fields such as photosensitive drums, thin film transistors, and image sensors, and their application range is becoming wider and wider. Also, the substrate for film formation has various shapes such as a cylindrical body and a flat plate, and its size is also various.

Under such circumstances, mass production technology is currently desired to be improved in order to reduce the manufacturing cost. For example, in a contact image sensor, a flat substrate is used, and for that purpose, a plasma CVD apparatus as shown in FIG. 2 has been proposed.

In the plasma CVD apparatus 1 of the same drawing, 2 is a vacuum container, 3 is a substrate holder, 4 is a substrate for film formation fixed to the substrate holder, and 5 is arranged to face the substrate 4. This is an electrode, and a plurality of ejection ports 6 for ejecting a gas for forming an amorphous silicon semiconductor layer are formed on the surface of the electrode 5 facing the substrate 4.

In the plasma CVD apparatus 1 having this structure, when the amorphous silicon-based semiconductor layer forming gas is blown out from the ejection port 6 and a voltage is applied between the substrate holder 3 and the electrode 5, plasma is generated. An amorphous silicon semiconductor layer is formed on the substrate 4 (hereinafter, amorphous silicon is abbreviated as a-Si).

[0006]

[Problems to be solved by the device]

 However, according to the above-mentioned proposed plasma CVD apparatus 1, since the a-Si semiconductor layer forming gas is blown to the plate surface of the fixed substrate 4, the gas is not evenly blown to the plate surface. There is a problem that it is not possible to form a film with a uniform film thickness on the plate surface of the substrate 4. Such a problem of non-uniform film formation is particularly noticeable in a substrate having a large area such as an image sensor for adhesion.

[0007]

[Means for solving problems]

 In the plasma CVD apparatus of the present invention, a regular polygonal tubular body and an electrode plate are opposed to each other in a reaction furnace, and a plurality of flat plate-shaped substrates are arranged on each peripheral surface of the tubular body to carry out reaction. While introducing the gas for forming an a-Si semiconductor layer into the furnace, the tubular body is rotated and a voltage is applied between the tubular body and the electrode plate or between the flat substrate and the electrode plate to generate plasma. Is generated, and the a-Si based semiconductor layer is simultaneously formed on the plurality of flat substrates.

[0008]

[Action]

 According to the plasma CVD apparatus having this configuration, since the regular polygonal cylindrical body having the plurality of flat plate-shaped substrates arranged on each peripheral surface rotates, the a-Si semiconductor layer growth on the plate surface of each substrate. The production gas is blown out evenly, so that a film having a uniform film thickness can be formed on the plate surface of the substrate 4.

[0009]

【Example】

 Embodiments of the present invention will be described below.

FIG. 1 is a schematic configuration diagram of a plasma CVD apparatus 7 of the present invention, in which 8 is a cylindrical reaction furnace made of a conductor, and the peripheral wall of this reaction furnace 8 has a double structure, The inside is a cylindrical electrode plate 9 for glow discharge. A regular hexagonal cylindrical body 10 made of a conductor is disposed inside the glow discharge electrode plate 9, and one of the output terminals of a high frequency power source (not shown) is connected to the glow plug via the outer peripheral wall of the reaction furnace 8. The discharge electrode plate 9 and the other terminal are connected to the tubular body 10, and a voltage is applied between the glow discharge electrode plate 9 and the tubular body 10. Further, an introduction hole 11 for the gas for forming an a-Si semiconductor layer is formed on the outer peripheral wall 8a of the reaction furnace 8, and a gas ejection hole 12 having a small diameter is formed on the entire electrode plate 9 for glow discharge. The gas for generating an a-Si semiconductor layer that has entered through the introduction hole 11 diffuses in the space region between the outer peripheral wall 8a of the reaction furnace and the electrode plate 9 for glow discharge, and more gas ejection holes are formed. It is blown from 12 toward the tubular body 10. Moreover, the cylindrical body 10 is rotated by a motor (not shown) during film formation.

Thus, in the above-described configuration, the long hexagonal substrate 13 having a size smaller than the surface of the peripheral wall is arranged on each peripheral wall of the regular hexagonal cylindrical body 10, and the cylindrical body 10 is rotated to cause gas ejection holes. When a gas for generating an a-Si semiconductor layer is blown from 12 and a voltage is further applied between the glow discharge electrode plate 9 and the tubular body 10, this causes each substrate 13 to rotate as the tubular body 10 rotates. Is exposed to the plasma region under uniform conditions, so that each substrate 13 is formed to have a uniform film thickness and quality.

Further, in the present invention, a plurality of film-forming substrates can be obtained at a time by arranging a plurality of the plasma CVD devices 7 and operating them simultaneously to form a film.

Furthermore, in the present invention, the present invention may be improved as follows.

For example, in the contact type image sensor, the a-Si based semiconductor layer used for the photoelectric conversion layer does not need to be formed on the entire main surface of the elongated substrate 13, Since an electrode pattern, an IC, and the like are mounted on, the a-Si system semiconductor layer may be formed into a predetermined shape by film formation. In many cases, an electrode pattern is previously formed of chromium or the like on the substrate 13 on which the film is to be formed, and an a-Si semiconductor layer having a predetermined shape is formed on the electrode pattern.

However, conventionally, it is formed on the entire main surface of the substrate 13 on which an electrode pattern is formed of chromium or the like, and then a resist is coated, and an unnecessary region of the a-Si based semiconductor layer is removed by etching. Is adopted.

However, according to this method, a problem is pointed out that the surface of the a-Si based semiconductor layer is contaminated by the organic substance of the resist and the semiconductor characteristics are deteriorated.

According to the present invention, the above problems can be solved as shown in FIGS.

3 and 4 show a method of fixing the substrate 13 to each peripheral wall of the tubular body 10, and FIG. 4 is a sectional view taken along line XX of FIG. In these figures, pressing plates 14 are arranged at both ends of the substrate 13, and the pressing plates 14 are fixed to the tubular body 10 with bolts 15. The region where the pressing plate 14 covers the substrate 13 is the non-film formation region of the a-Si based semiconductor layer.

Thus, according to the above configuration, the pressing plate 14 can also serve as a metal mask, and as a result, the etching plate is used to form the a-Si semiconductor layer having a predetermined shape as described above. As a result, the semiconductor characteristics of the a-Si based semiconductor layer do not deteriorate and the characteristics can be maintained.

The pressing plate 14 also serving as the metal mask may have a shape as shown in FIGS. 5 and 6. In the figure, 16 and 17 are the pressing plates.

Further, when the film is formed on the substrate 13 on which the electrode pattern is already formed of chromium or the like, the pressing plate 14 may be arranged as shown in FIG. In the figure, a chrome electrode 19 is formed on a glass substrate 18, a pressing plate 14 is arranged so as to cover a part of the chrome electrode 19, and the region of the chrome electrode 19 not covered by the pressing plate 14 is The a-Si based semiconductor layer may be formed as a film so as to cover it.

(Experimental Example) The inventors of the present invention conducted a film formation test using the plasma CVD apparatus 7 shown in FIG. A 232 × 56 mm glass substrate is used as the substrate 13, and the film formation area on the substrate is 220 × 56 mm. The film forming conditions are as follows: Glow discharge electrode plate 9 and tubular body 10: 40 mm, gas pressure: 0.4 to 1.0 Torr, high frequency power: 200 to 570 W, glow discharge electrode plate 9 size: Φ195 mm × 495 mm, the rotation speed of the cylindrical body 10: 6 rpm, and the gas component used for the same is SiH._Four, H ₂ , N₂, B₂H₆, PH₃, NH₃Etc.

When a film was formed for 136 minutes under such film forming conditions and the film forming test was repeated 10 times, the average value of the film thickness distribution was 7.2%. The average value of this film thickness distribution is the difference from the average by calculating the average of the maximum value and the minimum value and dividing the difference between the average value and the minimum value (or maximum value) by the average in each film formation test. The ratio was calculated, and the average value of all tests was calculated from the ratio of each test difference.

On the other hand, when a similar test was carried out using a conventional apparatus as shown in FIG. 2, the average value of the film thickness distribution was 11.3%, and in the present invention, a uniform film thickness was obtained. I was able to form a film.

The present invention is not limited to the above embodiment, and various improvements and changes can be made without departing from the present invention. For example, if the substrate for film formation is a conductor, that substrate may be used as one electrode and plasma may be generated between the substrate and the other electrode plate for glow discharge.

[0026]

[Effect of the device]

 As described above, according to the plasma CVD apparatus of the present invention, a plurality of flat plate-shaped substrates are arranged on each peripheral surface of a regular polygonal tubular body, and the tubular body is rotated and plasma is generated. The a-Si semiconductor layer forming gas is evenly blown to the plate surface of each substrate, and a film having a uniform film thickness can be formed on the plate surface of the substrate, resulting in a more uniform film quality. High quality and high reliability film formation was possible on each substrate.

In addition, according to the plasma CVD apparatus of the present invention, the pressing plate for fixing each substrate to the cylindrical body can also serve as a metal mask, whereby an a-Si based semiconductor having a predetermined shape can be obtained. There is also an advantage that it is not necessary to carry out etching for forming the layer to form a film, and as a result, the semiconductor characteristics of the a-Si based semiconductor layer are not deteriorated and the characteristics can be maintained.

[Brief description of drawings]

FIG. 1 is an explanatory view of a plasma CVD apparatus of the present invention.

FIG. 2 is an explanatory diagram of a conventional plasma CVD apparatus.

FIG. 3 is a perspective view of a tubular body according to the present invention.

4 is a sectional view taken along line XX of FIG.

FIG. 5 is an explanatory diagram of a method of fixing a substrate.

FIG. 6 is an explanatory diagram of a method of fixing a substrate.

FIG. 7 is an explanatory diagram of a method of fixing a substrate.

[Explanation of symbols]

 8 ... Reactor 9 ... Glow discharge electrode plate 10 ... Cylindrical body 13 ... Substrate

Claims (1)

[Scope of utility model registration request] 1. A regular polygonal cylindrical body and an electrode plate are opposed to each other in a reaction furnace, and a plurality of flat plate-shaped substrates are arranged on each peripheral surface of the cylindrical body to form an amorphous material in the reaction furnace. While introducing the silicon-based semiconductor layer forming gas, the cylindrical body is rotated and a voltage is applied between the cylindrical body and the electrode plate or between the flat plate-shaped substrate and the electrode plate to generate plasma. A plasma CVD apparatus that simultaneously deposits an amorphous silicon semiconductor layer on a flat substrate.