| 摘要 |
PURPOSE:To improve the yield of devices by a method wherein, after silicon ions are implanted into the rear surface of a single crystal silicon wafer, a protective film is applied to the back surface. CONSTITUTION:Silicon ions are implanted into the rear surface 3 of a single crystal silicon substrate 1. The back surface 3 is finished by etching after lapping. The substrate which is free from strain is employed. The ion implantation 4 is applied to the whole back surface with an accelerating voltage of 180 kV and density of 1X10<16>cm<-2>. After a protective film 5 is applied successively, a heat treatment is carried out at 1000 deg.C. By employing a silicon oxynitride film as the protective film, warpage and slipping of the wafer can be suppressed. Moreover, as silicon which is the same material as the material of the wafer is employed as implanted ions, the problem of contamination can be eliminated and, as silicon is electrically inactive, ions do not penetrate onto the front surface side of the substrate to vary the device characteristics.
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