JPS601780A - Infrared ray heat treating device - 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 Technical Field of the Invention The present invention relates to an infrared heat treatment apparatus, and more particularly to an apparatus for heat treating semiconductor wafers.

Background of the Technology In the process of manufacturing semiconductor devices, after impurity ions such as phosphorus and boron are implanted into a semiconductor wafer such as silicon, the wafer is subjected to heat treatment in order to activate the impurity ions.

Prior Art and Problems Conventionally, as shown in FIG. 1, rod-shaped infrared lamps such as tungsten lamps are provided on a silicon wafer 1, for example. The light 4 emitted from the tungsten rande 2 hits the reflecting plate 3 and is reflected onto the surface of the silicon wafer 1 as vertical light. For example, ions as impurities are activated in the silicon wafer 1 in advance. In the heat treatment for activating impurity ions, the silicon wafer 1 is heated so that the temperature distribution over the entire surface of the wafer becomes very uniform.
is rotated or moved at a constant speed.

However, as shown in Fig. 1(b), the intensity 5 of the light received by one silicon wafer 1 varies greatly depending on whether it is directly below the lamp or not (maximum Ts), and as shown in Fig. 2, one of the surface crystal defects In addition, due to insufficient diffusion of impurities implanted into the wafer, the distribution of layer resistance values is large, which worsens the stain characteristics.

The occurrence of such slip lines and deterioration of electrical characteristics have drawbacks that lead to a decrease in the yield of silicon wafers.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention aims to improve the temperature distribution of a semiconductor wafer in a heat treatment process of the semiconductor wafer, and to improve the generation of slip lines and the variation in layer resistance value in the semiconductor wafer using a method of infrared heat treatment. The purpose is to provide equipment.

Structure of the Invention An object of the present invention is to provide an apparatus for heat-treating a semiconductor substrate.
This is achieved by an infrared heat treatment apparatus characterized by comprising an infrared heating means above a semiconductor substrate and a reflecting plate having a diffused reflection surface to improve the thermal efficiency of the infrared heating means.

Examples of the invention Embodiments of the present invention will be described below based on the drawings.

FIG. 3 is a schematic diagram showing one embodiment of the present invention.

As shown in FIG. 3, a bar-shaped tungsten lamp 12 is conventionally arranged in parallel above a silicon wafer 11, and above the tungsten lamp 12 has a diffused reflection surface (
A reflecting plate made of (AtAu) is provided. Light 14 of about A is emitted from the tungsten lamp and is diffusely reflected by the reflecting plate 13.

By arranging a reflector having a diffused reflection surface in this way, a received light intensity distribution on the surface of the silicon wafer 11 as shown in FIG. 3(b) can be obtained. According to FIG. 3(b), as in the conventional case, the portion directly below the tungsten lamp has the highest temperature, but the difference from the lowest temperature is significantly smaller when comparing T2 with the conventional T1. That is, it has become possible to improve the temperature distribution during heat treatment of the silicon wafer 11. Furthermore, the diffused reflection plate used in the present invention may be made of (At/Ag) in addition to (At/p, u).

As described in detail, according to the present invention, the light emitted from the infrared lamp is diffusely reflected, making it possible to heat the semiconductor substrate more uniformly, thereby preventing the occurrence of slip lines and improving the electrical characteristics. It is also effective in improving yields.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic cross-sectional view for explaining one embodiment of a conventional infrared heat treatment apparatus, and FIG.
Fig. 2 is a plan view showing a silicon wafer in which slip lines have occurred, and Fig. 3 (-) shows the received light intensity of silicon wafer obtained using the method 1 according to the present invention. FIG. 3(b) is a schematic sectional view for explaining an example, and FIG. 3(b) shows the received light intensity of the silicon wafer obtained using FIG. 3(a). 1.11...Silicon wafer, 2.12...Tungsten lamp (infrared lamp), 3...Reflector, 4.
14... Light, 5, 15... Light intensity distribution (temperature distribution), 6... Slip line, 13... Diffuse reflecting plate. (b) □Location prefecture 2b) 389-

Claims (1)

[Claims] 1. An infrared heat treatment apparatus for heat treating a semiconductor substrate, comprising an infrared heating means and a diffuse reflection plate having a diffuse reflection surface above the semiconductor substrate.