| 摘要 |
PURPOSE:To improve characteristics through maintaining an effective gettering action and reducing harmful O-concentration between lattices by promoting separating of O between lattices with a C-atom and generating minute defects having a gettering effect. CONSTITUTION:When an Si substrate 1, of which the O-concentration between lattices is approximately 1.5X10<13>/cm<3> and the C-concentration is not less than 1X10<17>/cm<3>, is provided with a layer 4 of conducting type reverse to that of the substrate 1, which is buried therein upon processing under 1190 deg.C heat, a ragion 15, of which the O-concentration is low, is formed on the surface including the layer 4. If a thermally oxidized film 5 and a nitride film mask 6 are made on top the other, separating of O between lattices takes place in the substrate 1, and a region 16, in which a number of minute defects having a gettering effect are formed, is generated. The region 15 is of a low O-concentration and the defect generation is less than the region 16. Therefore, during the heat treatment impurities harmful to the region 15 and the layer 4 are subjected to a gettering effect in the region 16 by the minute defects caused by an O-educt, and the influence from the impurities can be eliminated. Thereafter, when a CMOS device is completed according to the conventional procedure, the leakage current is reduced and the characteristics are remarkably improved. |
