JPS60261126A - Manufacture of single crystal semiconductor film - Google Patents

Abstract

PURPOSE:To prevent strain in a wafer and the deformation of the wafer by fitting a plurality of cylindrical light sources in the same reflecting mirror, arranging one of the light sources at one focus of the reflecting mirror and a semiconductor substrate at the other focus of the reflecting mirror and thermally treating the semiconductor substrate. CONSTITUTION:A tungsten lamp 21 is set at one focus of an elliptical cylindrical reflecting mirror 23 and another tungsten lamp 22 in parallel with the lamp 21 while being separated from the lamp 21 by approximately 1cm. A wafer 24 is disposed at the other focus of the reflecting mirror 23 so that the surface of the wafer 24 is positioned. The wafer 24 is scanned in the direction of the arrow B in parallel at the speed of 1mm./sec. Accordingly, since a section preheated by beams from the lamp 22 is irradiated by beams from the lamp 21 and melted, strain in the wafer 24 and the deformation and breaking of the wafer 24 are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field 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 semiconductor film, specifically, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film, and more particularly, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film, and more specifically, a method for manufacturing a single crystal semiconductor film. This invention relates to a method of recrystallizing light by condensing light from a plurality of linear light sources using a mirror.

(2) Background of the technology A method of forming a single crystal semiconductor film whose crystal plane orientation matches the substrate surface on a dielectric film covering the surface of a single crystal semiconductor substrate is known (Japanese Unexamined Patent Publication No. 56-80125). ). Second
Referring to the perspective view of the figure, a silicon dioxide (5i02) film 2 is formed on the surface of a single crystal silicon substrate (wafer) 1 so as to expose a part of the substrate surface, and the exposed part of the substrate surface is formed on the 5j02 film 2. A non-single-crystal silicon (polysilicon or amorphous silicon) film 3 is deposited so as to be in contact with the non-single-crystal silicon film 3, and heat treatment is performed by scanning in the direction of arrow A while irradiating and heating the non-single-crystal silicon film 3 with a light beam 4 having a linear cross-section. The non-single crystal silicon film is made into a single crystal.

(3) Conventional technology and problems When the above-mentioned technology was actually implemented, when the light from a single rod-shaped heating element was focused and locally heated, distortion occurred within the wafer surface, resulting in deformation or destruction. It was confirmed that Therefore, if the light from the rod-shaped heating element is not focused on the wafer, the currently available lamps and resistance heating elements, unlike lasers and electron beams, lack energy density and recrystallize. become unable to do so.

Therefore, it is conceivable to arrange the rod-shaped heating elements 11.12 as shown in the modified example of FIG. Even if they are placed in contact with each other, the heating element and wafer 1
5 cannot be brought close to each other, the light utilization rate decreases, and there is a problem that recrystallization cannot be performed.

When using a laser beam, the diameter of the spot irradiated onto the wafer is approximately 100 μm, and since the wafer is irradiated with this spot, it takes time to heat the wafer. Recrystallization of the joint portion is not performed well, and a similar problem exists with the electron beam. However, when using a rod-shaped heating element, the wafer is scanned only once, so it does not take much time, and there is no seam that occurs when irradiating with a laser beam as described above, and it is effective in reducing costs. Therefore, there is a need for a heat treatment method using a rod-shaped heating element that does not cause the above-mentioned problems such as distortion and deformation.

(4) Purpose of the Invention In view of the above-mentioned conventional problems, the present invention provides a method for recrystallizing a non-single-crystalline semiconductor film using a rod-shaped heating element without causing distortion in the wafer, deformation of the wafer, or destruction of the single-crystalline semiconductor film. The present invention aims to provide a method for manufacturing a semiconductor film.

(5) Structure and object of the invention According to the present invention, in a method for recrystallizing a non-single crystal semiconductor film deposited on an insulating crotch of a semiconductor substrate by heat treatment, a plurality of rod-shaped light sources are provided in the same reflecting mirror. one of them is placed at one focal point of the reflecting mirror, and the semiconductor substrate is placed at the other focal point of the reflecting mirror,
This is achieved by providing a method for manufacturing a single crystal semiconductor film, characterized in that the substrate is heat-treated using a plurality of light sources to convert the non-single crystal semiconductor film into a single crystal semiconductor film.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

An embodiment of the present invention is shown in a front view in FIG. 1(a), in which 21 and 22 are rod-shaped tungsten lamps, 23 is an elliptical cylindrical reflecting mirror, and 24 is a semiconductor substrate (wafer). A tungsten lamp 21 is placed at one focal point of the elliptical cylinder reflector.
The other tungsten lamp 22 is set parallel to the lamp 21 at a distance of approximately 1 cm, and placed so that the surface of the wafer 24 is located at the other focal point of the elliptical cylinder reflector, so that the power from both lamps on the wafer 24 is As shown in FIG. 1 (bl), the wafer 24 is scanned in parallel in the direction of arrow B at 1 mm/sec so that the densities are 500 L' cm2 and 100 L' cm2, respectively.

In addition, in FIG. 1 (bl), the horizontal axis represents the position on the wafer,
The vertical axis represents the temperature of the wafer, and curves A and B represent the temperature due to lamps 21 and 22, respectively. As can be understood from the figure, since the portion preheated by the light from the lamp 22 is irradiated and melted by the light from the lamp 21, distortion within the wafer, deformation of the wafer, and destruction experienced in the conventional example are prevented. It was done. In fact, satisfactory results were obtained by heat treating a 0.5 μm thick polysilicon film (not shown) deposited on a SiO2 film on a wafer.

(7) Effects of the Invention As explained in detail above, according to the present invention, ■ Sufficient energy density necessary for recrystallization can be obtained by superimposing light from two rod-shaped lamps, and ■ By shifting the focal line of the lamp, the temperature gradient on the wafer can be smoothed and distortion can be prevented from concentrating.■ By putting two lamps in the same reflecting mirror, the device can be made more compact and light can be used more effectively. be. Note that although a tungsten lamp was used in the above example, the scope of application of the present invention is not limited to that case.

[Brief Description of the Drawings] Fig. 1 (al is a front view of the embodiment of the present invention, Fig. 1(b) is a diagram showing the temperature distribution of the wafer), Fig. 2 is a perspective view of the conventional example. 3 are front views of a modification of the conventional example. 2L 22--Single bar tungsten lamp, 23-Elliptical cylindrical reflector, 24-Wafer

Claims (1)

[Claims] In a method of recrystallizing a non-single crystal semiconductor film deposited on an insulating film of a semiconductor substrate by heat treatment, a plurality of rod-shaped light sources are arranged in the same reflecting mirror, and one of the rod-shaped light sources is set at the focal point of one of the reflecting mirrors. , and a single-crystal semiconductor characterized in that the semiconductor substrate is placed at the other focal point of the reflecting mirror, and the substrate is heat-treated by the plurality of light sources to convert the non-single-crystal semiconductor film into a single-crystal semiconductor film. Membrane manufacturing method.