JPS6247114A - Manufacture of semiconductor single crystal film - Google Patents

Abstract

PURPOSE:To emit a half ring-like laser light without loss of energy by inserting a lens of noncircular shape so that a focal point is positioned before a semiconductor substrate between a laser light oscillator and a semiconductor film. CONSTITUTION:A doughnutlike beam of laser light 12 oscillated by a laser light oscillator 11 is bent by a mirror 13 to be incident on a condensing lens 14. A semicircular convex lens 24 inserted between the lens 14 and a semiconductor substrate 16 to coincide in optical axis is disposed so that the focal point position 25 of the light 12 is disposed before the substrate 16. When the position 25 is adjusted,the light 12 incident on the lens 24 is largely refracted to be superposed with the light 12 passing a region having no lens 24. Thus, a light image of half ringlike beam of laser light can be obtained without reducing power of the light 12. Therefore, sufficient power can be obtained in case of recrystallizing a polycrystalline or amorphous semiconductor film on an insulator.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention produces a single crystal by melting a polycrystalline or amorphous semiconductor film formed on an insulator while scanning it with a continuous wave laser beam. The present invention relates to a method for manufacturing a semiconductor single crystal film that is made to have a chemical effect.

[Conventional technology]

FIG. 3 is a schematic diagram showing a conventional method for manufacturing a crystal film in a semiconductor. In the figure, (11) is a laser beam oscillator, (1
2) is a laser beam oscillated from a laser beam oscillator (11), (13) is a mirror that changes the optical path of the laser beam (12), (
14) is a condensing lens for condensing the laser beam (12), (15) is a shielding plate that blocks half of the laser beam (2), and (16) is a polycrystal formed on insulator-L. or 41
A semiconductor substrate having a high quality semiconductor film, (7) is a support stand that supports the semiconductor substrate (16) and heats it to an appropriate temperature;
12a) is a laser beam (
12) is the optical image.

Next, the operation will be explained. A donut-shaped laser beam (12) oscillated from a laser beam oscillator (11) is reflected by a mirror (13).
) etc., the semiconductor substrate (16) is focused by a condensing lens (14) to a diameter of 50 to 100 μm, and heated to about 400'c by a support base (17),
, L: 4 rays are irradiated. The support base (17) is scanned in the direction of the arrow in FIG. 3 at a speed of several cm to several]Ocm/sec. The structure is such that the latter half of the laser beam (12) in the scanning direction is not irradiated by the shielding plate (15).

Therefore, the laser beam (12) is transmitted to the optical image (
It is irradiated in a half-ring shape as shown in 12a). When such a laser beam (12) is irradiated onto a polycrystalline or amorphous semiconductor film deposited on an insulator, the laser beam (12)
Since the outside of the semiconductor film melted by is kept at a higher temperature than the central part, solidification and recrystallization occur continuously from the central part, and the semiconductor film grows into a single crystal film with large crystal grains.

[Problem that the invention seeks to solve]

The conventional method for manufacturing a semiconductor single crystal film is configured to obtain a half-ring-shaped laser beam (12) using a shielding plate (15).
12) does not reach the semiconductor substrate (16), and the laser beam (1
There was a problem in 2) that it was a large power fire.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a method for manufacturing a semiconductor single crystal film that can be irradiated with a semi-ring-shaped laser beam without the need for energy. do.

[Means for solving problems]

In the method for manufacturing a semiconductor single crystal film according to the present invention, a semicircular convex lens is inserted between a condenser lens and a semiconductor substrate so that its focal point is in front of the semiconductor substrate, and a laser beam is directed onto the semiconductor substrate -F. It irradiates light.

[Effect]

The semicircular convex lens of the present invention refracts the laser beam irradiated onto it and superimposes it on the laser beam in the area without the semicircular convex lens.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (11) is a laser beam oscillator, (12) is a laser beam, (13) is a mirror, (14) is a condensing lens that condenses the laser beam (12) to several tens of μm with a semiconductor substrate (16), (24) is the condenser lens (14) and the semiconductor base +7N(1
(6) is a semicircular convex lens inserted so that its optical axis coincides with the semiconductor substrate, (16) is a semiconductor substrate, and (17) is a support base that supports and heats the semiconductor substrate (16).

Next, the operation will be explained. A donut-shaped laser beam (12) oscillated from a laser beam oscillator (11) is transmitted through a mirror (1
3) and enters the condenser lens (14).

The position of the condensing lens (14) is adjusted so that the diameter of the laser beam (12) becomes several tens of μm on the semiconductor substrate (1G). Condenser lens (14) so that the optical axes match
The semicircular convex lens (24) inserted between the semiconductor substrate (16) and the laser beam (12)
) focal position i! (25) is adjusted so that it is in front of the semiconductor substrate (16). When the focal point position (25) is adjusted, the laser beam (I2) incident on the semicircular convex lens (24) is largely refracted, and the laser beam (I2) enters the semicircular convex lens (24).
It overlaps with the laser beam (12) that has passed through the area without. Therefore, without reducing the power of the laser beam (12) (
, a half-ring-shaped optical image (22b) of the laser beam (12) as shown in FIG. 2 is obtained. Therefore, sufficient power can be obtained when recrystallizing a polycrystalline or amorphous semiconductor film on an insulator.

In the above embodiment, the focal position of the semicircular convex lens (24) was adjusted so that there was no phase difference between the laser beams (12) to prevent interference.
If the intensity distribution is large at the periphery and low at the center, a pattern using interference fringes can also be used.

Further, the shape of the inserted convex lens (24) does not have to be semicircular, and even if it is fan-shaped, for example, the same effect can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, a semicircular convex lens is inserted between the condensing lens and the semiconductor substrate, so a semi-ring-shaped laser beam can be obtained without loss of laser power, and a large output power can be obtained from a single crystal. This has the effect of providing a method for manufacturing a semiconductor single crystal film that can perform chemical conversion.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a method for manufacturing a semiconductor single crystal film according to an embodiment of the present invention, FIG. 2 is a diagram showing an optical image of a laser beam in the method for manufacturing a semiconductor single crystal film shown in FIG. 1, and FIG. FIG. 3 is a schematic diagram of a conventional method for manufacturing a semiconductor single crystal film, and FIG. 4 is a diagram showing an optical image of a laser beam in the method for manufacturing a semiconductor T11 crystal film shown in FIG. (11) is a laser beam oscillator, (12) is a laser beam, (1
3) is a mirror, (14) is a condensing lens, (16) is a semiconductor substrate, (17) is a support stand, (24) is a semicircular convex lens,
(25) is the fμ point position, and (22b) is the optical image. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A method for manufacturing a semiconductor single-crystal film in which a polycrystalline or amorphous semiconductor film formed on an insulator is melted and recrystallized by a laser beam, including a laser beam oscillator that generates the laser beam and the laser beam. A method for manufacturing a semiconductor single crystal film, characterized in that a lens whose shape is not circular is inserted between the polycrystalline or amorphous semiconductor film to be irradiated with light. (2) The lens is a semicircular convex lens, and the focal position of the laser beam thereby is located in front of the semiconductor film, and the optical axis thereof coincides with the optical axis of the laser beam. A method for manufacturing a semiconductor single crystal film according to claim 1. (3) The method for manufacturing a semiconductor single crystal film according to claim 1 or 2, characterized in that a continuous wave argon laser beam is used as the laser beam.