JPH0526355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an amorphous semiconductor device equipped with a film substrate.

(b) Prior art Amorphous semiconductors based on amorphous silicon, which are formed by glow discharge in an atmosphere of silicon compounds such as silane (SiH ₄ ), are attracting attention as new semiconductor materials, and are currently being used in photovoltaic devices, optical sensors, etc. It has been put into practical use as active devices such as optical devices and thin film transistors.

Normally, amorphous semiconductors require a supporting substrate of some kind because they are thin, with a film thickness of several tens of micrometers or less, for example, about 4000 Å to 1 micrometer for photovoltaic devices. As is well known, an amorphous silicon based semiconductor film formed by glow discharge is heated to a temperature of approximately 200°C to 350°C on a supporting substrate.
It must be maintained at a temperature of about 0.degree. C., and furthermore, since the semiconductor film is deposited at a higher temperature, a film of better quality can be obtained, so such a supporting substrate is required to have heat resistance.

Therefore, glass and metals with high heat resistance have been used for a long time, and in particular, since glass substrates have insulating properties, it is possible to arrange a plurality of semiconductors electrically independent of each other, and It is most commonly used because it allows a semiconductor film to be arbitrarily wired on a substrate.

However, since the above-mentioned insulating substrate is made of glass, there is a risk of breakage. Therefore, as a new insulating substrate material, a flexible resin film made of heat-resistant resin such as polyimide resin or fluorine-based resin, which is free from the risk of breakage, has been developed. has come to appear.

However, the coefficient of linear expansion of such a resin film is larger than that of the amorphous semiconductor film to be deposited, and as a result of the film substrate being in an expanded state due to heating during the process of depositing the amorphous semiconductor film, it is difficult to return to normal temperature. At the same time, the above-mentioned difference in coefficient of linear expansion and shrinkage of the film substrate from its initial size due to heating and cooling have caused an accident in which the thin amorphous semiconductor film peels off. Furthermore, if the deposition temperature of the amorphous semiconductor film is lowered in order to prevent such a peeling accident, a semiconductor film of good quality cannot be obtained.

(c) Purpose of the Invention The present invention has been made in view of the above, and its purpose is to improve the use of flexible resin film substrates that do not have the risk of breakage, and to prevent peeling accidents of amorphous semiconductor films or deterioration of film quality. The goal is to make it possible without having to invite it.

(D) Structure of the Invention The present invention provides an amorphous semiconductor device comprising a flexible resin film substrate and an amorphous semiconductor film deposited on the substrate under heating conditions, in which the resin film substrate has linear expansion of the substrate. It is in the form of a structure that lowers the ratio and contains fiber as a core material.

(E) Example Figures 1 and 2 show an example in which the present invention is applied to a photovoltaic device, and 1 shows a film thickness of 80 μm to 400 μm.
The resin film substrate 1 is made of a heat-resistant polymer resin such as a flexible polyimide resin or a fluororesin, and the resin film substrate 1 is made of fibers such as glass fiber, carbon fiber, metal fiber, etc. as shown in FIG. It includes a woven core material 2 in which warp threads 2a and weft threads 2b are alternately knitted. 3a to 3d are a plurality of photoelectric conversion regions arranged in parallel on the film substrate 1,
The photoelectric conversion regions 3a to 3d include metal electrode layers 4a to 4d with a thickness of about 3000 Å to 1 μm divided into each region from the film substrate 1 side, and metal electrode layers 4a to 4d with a thickness of about 4000 Å to 1 μm continuously extending over each region. Amorphous semiconductor film 5 and a film thickness of 400 Å or more divided into each region
It has a laminated structure in which transparent electrode layers 6a to 6d made of tin oxide, indium tin oxide, etc. of about 700 Å are sequentially laminated. The amorphous semiconductor film 5 is made of, for example, hydrogenated amorphous silicon (a-SI:H) formed by glow discharge in an SiH ₄ gas atmosphere while the film substrate 1 is heated to approximately 200°C to 350°C. By adding appropriate impurity gas, it becomes
Has PIN junction.

7b to 7d are first connection terminals extending from each metal electrode layer 4b to 4d and exposed from the amorphous semiconductor film 5, and 8a to 8c are photoelectric conversion regions 3a adjacent to the left.
Hook-shaped second connection terminals extending from the transparent electrode layers 6a to 6c to be coupled to the first connection terminals 7b to 7d of ~3c, 9 and 10 are photoelectric conversion regions 3a at the right end or left end This is an external terminal extending from the 3d metal electrode layer 4a or the transparent electrode layer 6d.

In a photovoltaic device having such a configuration, when light is incident on the amorphous semiconductor film 5 through the transparent electrode layers 6a to 6d, the transparent electrode layers 6a to 6d and the metal electrode layer of each photoelectric conversion region 3a to 3d are A photovoltaic force is generated between 4a to 4d, and this photovoltaic force is electrically added by the coupling between the first connection terminals 7b to 7d and the second connection terminals 8a to 8c, and is transmitted from the external terminals 9 and 10. A series output is derived.

The feature of the present invention lies in the structure of the resin film substrate 1. That is, as shown in FIGS. 2 and 3,
The resin film substrate 1 used in the present invention contains fibers and has a lower coefficient of linear expansion than conventional substrates that do not contain fibers. For example, the coefficient of linear expansion of polyimide resin is approximately 30×10 ^-5 /°C, but as in this example, polyimide resin is used in the woven core material 2, which is made by alternately knitting warp threads 2a and weft threads 2b made of fibers. The coefficient of linear expansion of the film substrate 1 impregnated with and thermally cured is approximately equal to the coefficient of linear expansion of the core material 2, and is almost unrelated to that of the polyimide resin. Therefore, if soda lime glass is used as the fiber forming the core material 2, the coefficient of linear expansion of the film substrate 1 will be approximately 0.8 to 1.1×10 ^-5 /°C, and in the case of carbon fiber, it will be 0.54×10 ^-5 /°C. becomes. Furthermore, the presence of the core material 2 also improves the reduction in size from the initial size due to heating and cooling.

A polyimide resin film substrate 1 including such a core material 2 in the form of a woven glass fiber is commercially available from Toray Industries, Inc. under the trade name "Polyimide laminate TIL" and is suitable for use in the present invention.

In the case of the film substrate 1 having the core material 2 in the form of a woven fabric as described above, by aligning the longitudinal direction of the amorphous semiconductor film 5 with the direction of the weft 2b, the film substrate 1 can be easily attached to the amorphous semiconductor film 5. Expansion can be kept to a minimum.

Further, as for the form of the fibers included in the film substrate 1, the woven fabric core material 2 as in the above embodiment is optimal, but it may be either the warp thread 2a or the weft thread 2b, or it may be one in which short pitch fibers are mixed. It is still available for use.

Further, since the resin film substrate 1 made of polyimide is opaque, it has a laminated structure in which metal electrode layers 4a to 4d are arranged on the substrate 1 side and transparent electrode layers 6a to 6d are provided on the amorphous semiconductor film 5. However, when a transparent fluororesin, which is slightly inferior in heat resistance to polyimide resin, is used as the resin film substrate 1, the positions of the metal electrode layers 4a to 4d and the transparent electrode layers 6a to 6d are replaced, and the light is directed to the film substrate 1 side. It may also be a configuration derived from. Naturally, the fibers used at this time are transparent glass fibers.

FIGS. 4 and 5 show an embodiment in which a well-known thin film transistor 12 mainly composed of an amorphous semiconductor film 11 is formed using a film substrate 1 made of such a transparent fluororesin and a core material 2 of glass fiber. In the figure, 13 is a transparent electrode layer, 14 is a gate electrode of the thin film transistor 12, 15 and 16 are source and drain electrodes, and 17 is silicon nitride, etc., which electrically isolates the amorphous semiconductor layer 11 and the gate electrode 14. When an electric signal is applied to the gate electrode 14, the source and drain electrodes 15 and 16 become conductive, and an electric signal is applied to the transparent electrode layer 13.

A film substrate 1 on which such thin film transistors 12 are integrated in a matrix and each constitutes one pixel so as to perform switching operations independently, and a transparent electrode layer coated on the entire surface of the transparent resin film substrate are placed opposite to each other. By filling the opposing gap with liquid crystal, a flexible liquid crystal panel for pixel display can be obtained.

(F) Effects of the Invention As is clear from the above description, although the present invention uses a flexible resin film substrate with no risk of breakage, the linear expansion coefficient of the film substrate is lower than that of the fibers due to the inclusion of fibers. Since the difference in coefficient of linear expansion between the film substrate and the amorphous semiconductor film is reduced compared to the one not containing it, the difference in coefficient of linear expansion between the film substrate and the amorphous semiconductor film is reduced, and the difference in coefficient of linear expansion and the initial size are reduced when the film returns to room temperature. Accidental peeling of a thin amorphous semiconductor film caused by such factors can be prevented, and the deposition temperature of the amorphous semiconductor film can be increased, making it possible to obtain a high-quality semiconductor film.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
The figure is a sectional view taken along the -' line in Figure 1, and Figure 3A.
4 is a plan view showing the core material of the resin film substrate used in the present invention, FIG. 4 is an enlarged plan view thereof, FIG.
It is a sectional view taken along the line -' in the figure. 1... Resin film substrate, 2... Core material, 3a~
3d...Photoelectric conversion region, 5, 11...Amorphous semiconductor film, 12...Thin film transistor.

Claims (1)

[Claims] 1. In an amorphous semiconductor device comprising a flexible resin film substrate and an amorphous semiconductor film deposited on the substrate under heating, the resin film substrate has a core material in a form that reduces the coefficient of linear expansion of the substrate. An amorphous semiconductor device characterized by containing a fiber as an amorphous semiconductor device.