| 摘要 |
PURPOSE:To obtain a gas phase grown layer of high quality by processing in advance the surface of a substrate to form a buried diffused layer so that the density value of line defects L.D. is approx. prescribed value, thereby improving the getter effect of the substrate. CONSTITUTION:In order to obtain a composite substrate for a semiconductor bipolar IC device by forming a gas phase grown layer on the surface of a silicon substrate, the surface of a substrate to form a buried diffused layer is processed in advance so that the density value of line defects L.D. is approx. 10<3>- 10<4>. This L.D. value has reverse correlation with the S.F. value of the gas phase grown layer and in normal correlation with the yield of the gas phase grown layer. In this manner, the getter effect of the substrate can be preferably obtained, thereby gaining the gas phase grown layer of high quality. |
