| 摘要 |
PURPOSE:To obtain a semiconductor substrate without surface defects, by growing a low quality Si single crystal film on the back surface of the semiconductor substrate under specified conditions, thereafter thermally oxidizing the substrate, and forming a specified number of dislocations or lamination defects in the back surface. CONSTITUTION:The low quality single crystal film is grown on the back surface of the semiconductor substrate to the thickness of 0.5-2.5mum at 970 deg.C or more. Said substrate is thermally oxidized at a high temperature, and the dislocations or the lamination defects of aabout 10<5>/cm<2> or more are formed in the back surface of the substrate. For example, on the back surface of the Si substrate having no back surface strain, the Si film of about 0.6mum is grown by an SiH4/N2 series at the substrate temperature a of about 970 deg.C. Then, said substrate is thermally oxidized in wet O2 at 1,140 deg.C for about one hour, and oxide films of about 6,000Angstrom are formed on both sides of the substrate. Thus the substrate, in the back surface of which the dislocations of 10<5>-10<7>/cm<2> are introduced, is obtained. |
