摘要 |
PURPOSE:To perform gettering treatment in an arbitrary element forming process and improve the yield of elements, by keeping the surface of a substrate whereon elements are formed at a low temperature when fusion-diffusing phosphorus by the irradiation of laser light, after a phosphorus glass layer is provided on the back surface. CONSTITUTION:After an N<+> type buried layer 12 is formed, an N type epitaxial layer 13 is formed, and an insulation isolated oxide film 14 is formed by using a P type Si substrate 11, a gettering treatment by this prevention, i.e. a process wherein laser light l is irradiated is performed after providing the phosphorus glass layer on the back surface. Thereafter, a P type base region, an N<+> type emitter region 22 and an N<+> type collector region 23 are formed, and an electrode region 24 is formed resulting in the manufacture of an isoplanar type bipolar transistor having a back surface gettering region 25. |