JPS6439732A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an SOI substrate having a single crystalline silicon layer of high quality over a large area by placing glass powder on a silicon wafer, and heat treating it at a temperature equal to or higher than the softening point of the powder in a reduced pressure atmosphere. CONSTITUTION:Glass powder 2 is placed on a silicon wafer 1. Then, a single crystalline silicon wafer 1 which places the powder 2 is contained in a sealed vessel, which is in a reduced pressure atmosphere, and heated at a temperature equal to or higher than the softening point of the powder 2. The powder 2 is softened in this step to form a uniform glass layer 3 on the wafer 1. Then, the wafer 1 is reduced to a thin film by both mechanical polishing and chemical polishing to form a silicon layer 4. By this method of manufacture, since an insulating substrate (glass) is formed on the wafer, an SOI substrate having the same area as that of the wafer can be obtained, the silicon thin film is a part of the wafer to obtain a silicon layer of high quality. Since the glass layer is obtained by softening it under the reduced pressure atmosphere, the transparent glass layer of high quality is obtained.