| 摘要 |
PURPOSE:To inhibit the generation of a slip defect, and to improve the yield of an LSI by forming the strain field of a ground layer and a polysilicon film to the back of a substrate in low oxygen concentration. CONSTITUTION:A ground layer 13 is shaped onto the back of an silicon substrate 11 in initial oxygen concentration of 1X10<18>atoms/cc or less in depth of - 20mum. A polysilicon film 14 is attached onto the ground layer 13 in 1-2mum. Defects 15 by the ground layer and defects 15 by the grain boundary stress of the polysilicon film are generated at every thermal oxidation in the substrate, and function as strong getters, and impurities (heavy metals) intruding from the surface of the substrate are captured by the layers 13, 14, 15 during the process. Tensile stress operates to the substrate 11 by the ground layer 13 and the polysilicon film 14, and the warpage of a wafer during a thermal process is relaxed, thus inhibiting the generation of slip defects. |
