| 摘要 |
PURPOSE:To make out easily a minute base region by forming self-matchingly an emitter region and a base region with only a necessary mask at an opening of the emitter region. CONSTITUTION:After an insulating film 3, a P<+> poly Si 10 and a coat 11 are formed on an N type epitaxial layer 2 on an Si substrate 1, an opening 12 is formed through eliminating the film 3, Si 10 and the film 11 equivalent to the opening of the emitter region. After an opening 13 of a projected installation region of a base electrode is formed, an oxidation-resistance coat 14 is formed at the bottom of the opening 12 and the film 11. A P<+> poly Si becoming the base electrode is formed through the opening 13 by eliminating the film 14 on the film 11 with an elimination of the film 11. An exposed part of Si 15 is reformed into an oxide film 16 through a thermal oxidation. A base compensating region 4 is formed with diffusing P type impurities from Si 15. After an opening 17 is formed through eliminating the film 14, an intrinsic base region 5 and the emitter region 6 are formed with an injection of a P type and an N type impurities through the opening 17. |
