JPH046822A - Method for manufacturing crystalline semiconductor thin film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present study relates to a method for manufacturing a crystalline semiconductor thin film,
It is most suitable for use in forming a lator structure.

[Conventional technology]

As a conventional example of a method for manufacturing a crystalline semiconductor thin film, JP-A-61
There is one described in JP-288413. FIG. 3(a) to FIG. 2(C) are process-order sectional views showing a conventional example. The following will be explained based on the drawings.

First, as shown in FIG. 3(a), a quartz substrate l is prepared.

After forming a polycrystalline Si film (polycrystalline silicon film) 11 thereon by low-pressure vapor phase epitaxy, as shown in FIG.
An in2 film (silicon dioxide film) 12 is laminated. next,
The polycrystalline 51M1ll is melted and crystallized by irradiating the laser beam 3 to form a single crystal 5il as shown in FIG. 3(C).
i (single crystal silicon film) 13. The 5in2 film 12 suppresses the flow of silicon caused by the melting of the polycrystalline Si film 11 during laser irradiation, and solidifies the monocrystalline Si film 1 after cooling.
The surface of the 5in2 film 12 becomes flatter than that without the 5in2 film 12.

[Problem to be solved by the invention]

However, when the laser beam 3 is irradiated to the polycrystalline Si film 11 through the 5in2 film 12, the crystallized 5ill actually created has irregular grain boundaries like the crystallized Si film 14 in FIG. Become. This is because growth nuclei of silicon crystals occur due to irregular positions in the molten silicon film, and adjacent silicon crystals in the silicon film prevent each other from growing, resulting in regular acid-free grains. This will form a world. Another problem is that the grain sizes of the silicon crystals in the crystallized 5iH1d thus formed are uneven, and the physical properties of the silicon film vary considerably depending on the location of the film.

The present invention aims to provide a method for manufacturing a crystalline semiconductor thin film that can correct the above-mentioned problems of the prior art and can obtain a silicon film having controlled grain boundaries and an arbitrarily specified grain size. purpose.

[Means to solve the problem]

In order to solve the above-mentioned problems, a method for manufacturing a crystalline semiconductor thin film according to the present invention provides a crystalline semiconductor film in which a polycrystalline semiconductor film is obtained by crystallizing an amorphous semiconductor film formed on an insulating substrate. In the method for manufacturing a semiconductor thin film, a first amorphous semiconductor film is formed on the insulating substrate, and is left in an island shape by photolithography and irradiated with a laser beam to crystallize the first amorphous semiconductor film. a step of obtaining a crystalline semiconductor film; a step of laminating a resist film on the single-crystal semiconductor film to leave a central region of the single-crystal semiconductor film in an island shape;
forming a second amorphous semiconductor film covering the resist film and the exposed insulating substrate; and removing the resist film and the second amorphous semiconductor film on the resist film; The present invention is characterized in that a crystalline semiconductor film is formed by performing crystal growth using the single crystal semiconductor film as a nucleus by heat treatment at a temperature of .degree. C. or higher.

〔Example〕

The method for manufacturing a crystalline semiconductor thin film according to the present invention will be described below.
An example applied to the formation of a structure will be described with reference to the drawings.

First, as shown in FIG. 1(a), a first amorphous Si film 2 is formed on an insulating substrate 1 by, for example, plasma chemical vapor deposition, and then a laser beam 3 is irradiated to form the first amorphous Si film 2. Sex S
The T film 2 is melted and crystallized, and the crystallized single crystal Si film 4 is left in an island shape by photolithography using a resist film 5 as a mask and chemically etched as shown in FIG. 1(b). . Subsequently, as shown in FIG. 1(c), a second amorphous Si film 6 is deposited by, for example, plasma chemical vapor deposition with the resist film 5 remaining.

At this time, the second amorphous Si film 6 is formed on the exposed insulating substrate 1 and the resist film 5, but the film thickness is made to be the same as that of the single crystal Si film 4. Next, as shown in FIG. 1C, the resist film 5 is selectively etched and removed together with the second amorphous Si film 6 on the resist film 5. Through this step, a flat thin film consisting of the single crystal Si film 4 and the second amorphous Si film 6 is formed on the insulating substrate 1. Further, as shown in FIG. 1(e), crystal growth is performed by heat treatment at 500° C. or higher using the single crystal Si film 4 as a growth nucleus to form a crystalline Si film 9 having crystal grain interfaces 8. Figure 1(d)
Crystallization by heat treatment using the single-crystal Si film 4 as a crystal growth nucleus shown in FIG.

Therefore, if the heat treatment time is shortened, as shown in FIG. It is possible to obtain a semiconductive thin film. therefore,
The crystal grain size of the crystalline Si film 9 can be controlled by the heat treatment time. Furthermore, the grain size of the crystals is also the same.

In addition, the crystal grain size is controlled and single crystal S becomes the nucleus for crystal growth.
Since the position of the i-film 4 can be easily controlled, the position of the crystal grain interface 8 shown in FIG. 1(e) can also be controlled.

〔Effect of the invention〕

The method for producing a crystalline semiconductor thin film according to the present invention realizes a uniform crystal grain size with an arbitrary size, and furthermore, the position of the crystal grains can be controlled to a predetermined position, and a flat crystalline semiconductor thin film can be obtained. This has the effect that it is possible to

[Brief explanation of the drawing]

1(a) to (e) and FIG. 2 are cross-sectional views showing an example in which the method for manufacturing a crystalline semiconductor thin film of the present invention is applied to the formation of a Sol structure. 3(a) to 4(C) and FIG. 4 are cross-sectional views showing an example of a conventional method for manufacturing a crystalline semiconductor thin film. φ resist film, second amorphous St film, grain boundary, crystalline Si film Applicant: Seiko Epson Corporation Representative Patent attorney: Kizobe Suzuki (and 1 other person) 1... Insulating substrate 2...・First amorphous Si film 3...Racer beam 4...Single crystal S1 film Crystalline narrowing Fig. 7 Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] In a method for producing a crystalline semiconductor thin film in which a polycrystalline semiconductor film is obtained by crystallizing an amorphous semiconductor film formed on an insulating substrate, a first
forming an amorphous semiconductor film and leaving it in an island shape using a photolithography method and irradiating the first amorphous semiconductor film with a laser beam to crystallize the first amorphous semiconductor film to obtain a single crystal semiconductor film; and applying a resist to the single crystal semiconductor film. a step of stacking films to leave a central region of the single crystal semiconductor film in an island shape; a step of forming a second amorphous semiconductor film to cover the resist film and the exposed insulating substrate; After removing the film and the second amorphous semiconductor film on the resist film, a crystalline semiconductor film is formed by performing crystal growth using the single crystal semiconductor film as a nucleus by heat treatment at 500° C. or higher. A method for producing a crystalline semiconductor thin film.