JPH03185822A - Heating method of semiconductor substrate - Google Patents

Abstract

PURPOSE:To facilitate automatic annealing, and easily eliminate crystal defect from a surface, by heating the rear of a semiconductor wafer substrate like an Si wafer, with lamp light or laser light, to fuse the rear, and keeping the temperature of the substrate surface lower than or equal to the melting point. CONSTITUTION:When the rear facing the mirror surface 2 of an Si wafer 1 is irradiated with the light 4 of a lamp such as halogen lamp, xenon lamp, and argon lamp or laser light, the temperature of the rear of the Si wafer 1 becomes higher than or equal to 1405 deg.C, the melting point of Si. A fused layer 3 of 2-5mum in thickness is formed as the result of fusing. The reflectivity of the fused layer 3 for the lamp light 4 becomes high, so that said layer is maintained as it is. The temperature of the part containing the mirror surface 2 of the Si wafer except the fused layer 3 is automatically kept lower than or equal to 1405 deg.C, the melting point of Si. Thereby high temperature heat treatment is facilitated, and crystal defect can be effectively eliminated from the Si wafer surface. The fused layer 3 is hardened by interrupting the heating.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a new method for heating semiconductor substrates at high temperatures.

[Prior Art] Conventionally, methods for heating semiconductor substrates include introducing the semiconductor substrate into a furnace whose temperature is controlled to be uniform so that the front and back surfaces of the semiconductor substrate are at the same temperature as much as possible. It was getting worse.

[Problems to be Solved by the Invention] However, according to the above-mentioned prior art, there is a problem in that when the heating temperature approaches the melting point of the semiconductor material, the semiconductor substrate melts due to slight fluctuations or variations in temperature.

An object of the present invention is to solve the problems of the prior art and to provide a new method for heating a semiconductor substrate at a high temperature in which at least the surface of the semiconductor substrate does not melt even when heated at a high temperature.

[Means for Solving 'liAM] In order to solve the above problems, the present invention relates to a method for heating a semiconductor substrate, which involves heating the back surface of a semiconductor wafer substrate such as a Si wafer with lamp light or laser light to melt it. , measures are taken to automatically maintain the surface of the semiconductor wafer substrate, such as the Si wafer, at a temperature close to the melting point or below.

[Example code] Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 is a schematic cross-sectional view showing a method of heating a Si wafer according to an embodiment of the present invention. That is, Si wafer 1
When the back surface facing the mirror surface 2 of the Si wafer 1 is irradiated with wrap light 4 such as a halogen lamp, xenon lamp, argon lamp, or laser beam, the back surface of the Si wafer 1 becomes 8i melting point 1405'O or higher and has a thickness of 2 to 5 μm ( 1
) #l! A melting layer 5 is formed and melted. At that time, the reflectance of the melted layer 30 to the lamp light 4 increases, and while the melted layer 3 is maintained, the melted layer 5 including the mirror surface 2 of the Si wafer
The other portions are automatically kept below the melting point of Sl, 1405° C., so that high-temperature heat treatment can be easily performed, and crystal defects can be efficiently removed from the Si wafer surface. Thereafter, the molten layer 5 solidifies when the heating is stopped. The present invention can be applied not only to Si wafers but also to other semiconductor substrates such as GaAθ wafers.

Furthermore, the present invention is applicable not only to semiconductor substrates but also to ultra-quadratic substrates, etc.
Can be applied to other material substrates, etc. [Effects of the Invention] According to the present invention, a semiconductor substrate can be easily and automatically annealed at a temperature close to the melting point, and crystal defects can be removed from the surface of the semiconductor substrate, etc. etc. can be easily carried out.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing a method of heating a semiconductor substrate according to an embodiment of the present invention. 1...Si wafer 2...Mirror surface 3...Melted layer 4...More than lamp light

Claims (1)

[Claims] A semiconductor substrate characterized in that the back surface of a semiconductor wafer substrate such as a Si wafer is heated and melted with lamp light or laser light, and the surface of the semiconductor wafer substrate such as the Si wafer is maintained at a temperature near the melting point but below the melting point. heating method.