| 摘要 |
PURPOSE:To obtain a walled emitter type semiconductor device having a shallow junction wherein a base junction depth does not vary by shortening the heat treatment time at a post process and reducing the temperature by forming an active base region after selectively oxidizing a polycrystalline Si film. CONSTITUTION:An isolation oxide film 24 is formed in a structure having a P type semiconductor substrate 21, an N type buried layer 22, and an N epitaxial layer 23, a polycrystalline Si 25 and an Si nitride film 26 are deposited, and a P type inactive base region 29 is formed by boron ion implantation. An Si oxide film 30 is formed by selectively oxidizing the polycrystalline Si film 25. It is selectively covered with the polycrystalline Si film 31, and boron ion implantation is performed, thus forming a base contact region 32. It is selectively covered with a polycrystalline Si film 33, and boron ion implantation is performed, resulting in the formation of the active base region 34, and then a shallow emitter region 35 is formed by arsenide or phosphorus ion implantation. The junction depth of the active base region can be restricted to the value at the time of ion implantation, and the emitter junction can be made shallow. |
