| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that gettering power is deficient in both EG and IG added to a step for doping nitrogen. SOLUTION: A silicon wafer 1' is subjected to a step for doping nitrogen, an extrinsic gettering (EG) step, and a step for forming a polysilicon wafer 3, for example. Even if the silicon wafer is exposed to heavy metal ions of copper, nickel, or the like, in the device process, intrinsic gettering (IG) acts in the heat treatment process to capture the copper and nickel. Since the polysilicon wafer 3 is formed as a strain layer, iron and copper can be captured through action of extrinsic gettering (EG) using the polysilicon wafer 3 as the base of capturing. COPYRIGHT: (C)2003,JPO
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