JPS61289619A - Manufacture of single-crystal silicon film - Google Patents

Abstract

PURPOSE:To form a single-crystal silicon film on the substrate without damaging the transparency of the substrate by a method wherein a photo absorption layer is provided on the back surface of the substrate, a semiconductor layer is formed by adhesion in the vicinity of the end part on one side of the surface of the substrate, the light irradiation means and the substrate are made to move from the end part side, whereon the single-crystal generating part is formed, and the amorphous silicon film being formed on the substrate is made to single-crystallize in order. CONSTITUTION:A substrate 2, whereon an amorphous silicon film 3 is formed, is made to move to the direction shown by an arrow B under the lower sides of tungsten- halogen lamps 5. The relative shift between this substrate 2 and the layers 5 is set in such a way that the groove 2a of the substrate 2 is first irradiated with the light of lamps 5, then the relative shift moves in order to the opposite side of the substrate to the groove 2a. The irradiation light to be emitted from the tungsten-halogen lamps 5 passes through the amorphous silicon film 3 and the quartz substrate 2 and is adsorbed in a silicon wafer 1, the silicon wafer 1 emits heat due to this photo absorption and the substrate is heated by heat transmission. In this case, part of the amorphous silicon film 3, which is formed in the groove 2a, is first fused, is made to single- crystallize and is converted into a single-crystal silicon film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a single crystal semiconductor film, and more particularly to a method for manufacturing a single crystal silicon film having a particularly large surface.

In order to epitaxially grow silicon on an amorphous substrate, it is necessary to form a seed crystal on the substrate that will serve as the nucleus for single crystal growth. The structure was designed to generate

For example, a method has been proposed in which a silicon wafer is coated with silicon dioxide or silicon, a portion of the underlying silicon is exposed, and an epitaxial layer is formed by laser annealing using this as a seed crystal. However, in the case where seed crystals are generated by dispersing them over the entire surface of the substrate and single crystals are grown from these seed crystals, it is necessary to form a large number of crystal generating areas on the substrate, which causes processing problems. Along with difficulties,
There are drawbacks such as non-uniform properties of the substrate and imperfect crystallinity of the grown single crystal film.

1-1 The present invention has been made in view of the above points, and it is an object of the present invention to eliminate the drawbacks of the prior art as described above and to provide an improved method for manufacturing a single crystal semiconductor film.

l-Imaginary According to the present invention, a semiconductor layer made of a selected semiconductor material is attached to the surface of a transparent substrate having a light absorption layer on the back surface and a single crystal generating portion formed near one end of the front surface. A light irradiation means capable of irradiating light that is formed and absorbed by the light absorption layer and the substrate are moved relative to each other from the end side where the single crystal generation portion is formed, and the semiconductor layer is exposed to the single crystal. There is provided a method for manufacturing a single crystal film, characterized in that the single crystal film is sequentially formed from the generation portion along the surface. In a preferred embodiment, the method is applied to forming a single crystal silicon film on a transparent substrate such as quartz, and a complete single crystal silicon film is formed on the substrate without any loss of transparency of the substrate.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show one embodiment of the present invention, and as shown in the figures, a light absorption layer 1 is provided on the back side of a transparent and electrically insulating substrate 2 made of a material such as quartz. I'm being kicked.

This light absorption layer 1 is formed from a material that can actively absorb irradiated light, which will be described later. The light absorbing layer 1 may be placed on top of the light absorbing layer 1.
Any material may be used as long as it is capable of absorbing irradiated light and converting the absorbed light into thermal energy.In addition to the silicon wafer mentioned above, Mo.

It is also possible to use metals such as W, Ta%Al, Fe, Ni, and Cr, alumina, and the like. The light absorption layer 1 is preferably made of a material having an absorption band within the range of 0.5 to 3.5μ, and the transparent substrate 2 is preferably a quartz substrate manufactured by Corning Co., Ltd., such as 7759 or 7740. It is possible to use it for

In the illustrated example, a groove 2a is formed on the surface of the substrate 2 near the left end thereof.

This groove 2a functions as a single crystal generating portion. In a preferred embodiment, the depth D of this groove 2a is 54.5 mm.
3n intestine to 5.43 μm, and its length L is 5.43 μm.
43μ- to 543μ koji, and its width W is 5゜4.
The value is within the range of 3 μm to 543 μm. Groove 2 like this
As an example of forming the quartz substrate 2, patterning is performed on the quartz substrate 2, and etching is performed using an etchant of, for example, HF:HNO,=1:6, for a time of about 1 second to 480 seconds.

On the surface of the substrate 2 with grooves 2a carved in this way.

A semiconductor layer 3 is formed from the selected semiconductor material.

In a preferred embodiment, an amorphous, microcrystalline, or polycrystalline silicon film is formed by glow discharge or pyrolysis to about 1.
Form to a thickness of about 0μ intestine. As an example, plasma C
When forming the amorphous silicon layer 3 by the VD method, SiH4 diluted 10 to 100% with H8 is used, the substrate temperature is 200 to 350°C, and the pressure is 0.01.
The amorphous silicon film 3 is formed to a thickness of 0.3 to 10 .mu.m at a pressure of 0.2 Torr to 0.2 Torr, an RF power of 0.5 to SOW, and a gas flow rate of 5iH9 of 1 to 303 CCM. The silicon film 3 formed in this manner generally has an amorphous, microcrystalline, or polycrystalline structure rather than a single crystal structure.

Next, as shown in FIG.
Move it in the direction of. In this case, the board 2 and the lamp 5
The relative movement between the lamps and the grooves 2a of the substrate 2 is determined such that the groove 2a of the substrate 2 is first irradiated with the lamp and then sequentially moves to the opposite side of the substrate 2.

Incidentally, the lamp 5 may be moved while the substrate 2 is kept stationary.A reflection plate 6 is disposed above the lamp 5.
All the light emitted from the lamp 5 is directed toward the substrate 2 as much as possible.

Therefore, the irradiated light from the tungsten halogen lamp 5 substantially passes through the amorphous silicon film 3 and the quartz substrate 2 and is absorbed into the silicon wafer 1.
generates heat due to this light absorption, and heats the substrate 2 by thermal conduction. This state is shown by arrow C in FIG. In this case, the amorphous silicon portion formed within the groove 2a is first melted and crystallized to be converted into single crystal silicon. As a result, the silicon portion single-crystalized within the groove 2a acts as a seed crystal, and as the substrate 2 is moved in the direction of arrow B, the amorphous silicon 3 gradually forms the single-crystal silicon 3a along the surface of the substrate 2. is converted to That is, as the substrate 2 and the lamp 5 are moved relative to each other, heating due to light absorption in the silicon wafer 1 progresses sequentially along the surface of the substrate 2, and the amorphous silicon 3 and single crystal silicon 3a
The interface 4 progresses in sequence in the direction of arrow A.

In this case, the atomic orientation of the silicon film 3 is restricted by the groove 28 portion. Since the lattice constant of silicon is 5.43, when silicon is used, the dimensions of the grooves 2a must be selected to be a multiple of this. When the silicon atoms have been oriented in the groove 2a, the substrate 2 is moved relative to the lamp 5, as shown in FIG. 2, and silicon is single crystallized over the entire surface of the substrate. In this case, the lamp annealing conditions are, for example, an annealing temperature of 800°C.
to 1, at 200°C, in an inert gas such as nitrogen or argon, and at a relative conveyance speed of 1117 seconds to 100/
It is best to set it to seconds.

3 and 4 show another embodiment of the invention. In this embodiment, a silicon seed crystal 3b is buried in a groove 2b formed in a substrate 2, and a silicon film 3 is formed thereon. The substrate 2 therefore provides a substantially flat surface since its grooves 2b are filled with silicon seed crystals 3b. The substrate 2 on which the silicon film 3 has been deposited in this manner is passed under the tungsten-halogen lamp 5 from the side filled with the seed crystal 3b, as shown in FIG. In this case as well, when the silicon wafer 1 heats the silicon film 3 by heat conduction via the substrate 2 due to light absorption.

First, single crystallization starts from the portion that is in contact with the seed crystal 3b, and single crystallization progresses sequentially along the surface of the substrate 2 in the direction of arrow A.

In each of the above embodiments, when the silicon film 3 is made into a single crystal, it becomes possible to directly absorb the irradiation light from the tungsten halogen lamp 5 and self-heat. Once single crystallization is started, the crystallization process along the substrate 2 progresses at an accelerated rate.

Further, the grooves 2a and 2b can be formed in various shapes, and by specifying the shapes, it is possible to freely control the orientation plane of silicon. As an example, as shown in FIG.
On the other hand, if the angle θ3 of the inverted pyramid groove 9 is set to 109.5 degrees, single crystal silicon having an orientation plane (110) is formed.

As detailed above, according to the present invention, it is possible to form a single crystal silicon layer on a transparent insulating substrate, and it is possible to integrally form a same-size sensor and a drive circuit for a liquid crystal display. Since the grooves formed on the transparent insulating substrate are only partially formed at the side edges, and the seed crystals are extremely local, it may damage the properties of the substrate itself, such as its transparency. It is possible to form a single-crystal silicon film without the need for a single-crystal silicon film.

Furthermore, it is possible to easily form a single crystal silicon film with uniform characteristics over a large area.

Although specific embodiments of the present invention have been described in detail above, the present invention should not be limited only to these specific examples, and various modifications may be made without departing from the technical scope of the present invention. Of course, it is possible.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams showing one example of implementing the present invention, Figures 3 and 4 are explanatory diagrams showing another example of implementing the present invention, and Figure 5 is a further example. It is an explanatory diagram showing an example of. (Explanation of symbols) 1: Light absorption layer 2: Substrate 3: Silicon film Patent applicant Ricoh Co., Ltd.
- 20th

Claims (1)

[Scope of Claims] 1. A semiconductor layer made of a selected semiconductor material is deposited on the surface of a transparent substrate, which has a light absorption layer on the back surface and a single crystal generating region near one end of the surface. A light irradiation means capable of irradiating light absorbed by the light absorption layer and the substrate are moved relative to each other from the end side where the single crystal generation portion is formed, and the semiconductor layer is exposed to the single crystal generation portion. 1. A method for producing a single crystal film, comprising sequentially forming a single crystal along the surface from the top. 2. The method of claim 1, wherein the semiconductor material is silicon. 3. The method according to claim 2, wherein the light absorption layer is a silicon wafer, and the substrate is placed on the silicon wafer. 4. The method according to claim 3, wherein the substrate is quartz and the light irradiation means is a tungsten halogen lamp. 5. The method according to claim 1, wherein the single crystal generating portion is a groove of a predetermined shape formed on the surface of the substrate. 6. The method according to claim 1, wherein the single crystal generating portion is a seed crystal embedded in the substrate.