| 摘要 |
PURPOSE:To prevent damage by plasma to be inflicted on the etching of polysilicon, and to obtain a bipolar transistor having excellent transistor gains and noise characteristics by coating single crystal silicon in a base contact with an silicide layer of a high melting-point metal. CONSTITUTION:An N<+> type floating collector layer 2, an N-type epitaxial growth layer 3, a deep N<+> diffusion layer 4, a P-type base layer 5 and an isolation oxide film 6 surrounding these forming regions are formed onto a P-type silicon substrate 1, an oxide film 7 is shaped onto an upper surface, and a base contact-hole 20, openings 40, 30 for forming a collector contact layer and an emitter layer are shaped to the oxide film 7. A high melting-point metal is deposited on the whole surface, and a high melting-point metal layer 12 is formed only on the base contact 20. An silicide layer 13 of the high melting- point metal is formed through heat treatment, and polysilicon 8 is deposited on the whole surface. Only polysilicon 18 on the opening 30 for shaping the emitter layer is left through a patterning by a resist 14, and other polysilicon is plasma-etched by using Freon gas, etc. |
