| 摘要 |
PURPOSE:To enable forming a non-defective area in a surface layer and an internal high density minutely defective area while suppressing or preventing warping by using flush light in part or all of the heat treatment processes. CONSTITUTION:The temperature of a wafer 21 surface illuminated with flush light rises and supersaturated oxygen is separated near the surface whereby a minutely defective nucleus 22 is formed. In this process, the minutely defective nucleus is not formed extremely near the surface since the super-saturated oxygen escapes outside the wafer. When an LSI is manufactured using the wafer, the minutely defective nucleus 22 is grown around a minutely defective nucleus by heat treatment in the manufacturing processes but a non-defective area 23 is formed in a surface layer since no nucleus exists at the extreme surface and a high density minutely defective area 24 is formed in deeper portion whereby an IG wafer is formed. Since flush light is used in the heat treatment, the time of process is reduced, warping of IG wafer is prevented and generation of defect in the non-defective area 23 due to warping can be prevented. |
