| 摘要 |
PURPOSE:To improve the performance of a semiconductor device largely by forming a weld emitter type transistor and a transistor, which does not belong to a weld emitter type, in a semiconductor device in the same substrate. CONSTITUTION:An N type substrate or an N type epitaxial layer 21 is oxidized selectively, a field oxide film 22 is formed in approximately 1.3mum, and a base impurity is introduced to form base regions 11, 11'. Polysilicon 24, 24' in approximately 5,000Angstrom thickness is shaped, and oxide films 23, 23' are formed through selective oxidation. An N type impurity is introduced to polysilicon, and emitter regions 12, 12' are formed by a diffusion from the polysilicon. When an emitter window is shaped so as to overlap to the edge 11a of the base region 11 and the impurity is introduced at that time, the weld emitter 12, a periphery thereof is surrounded by an insulating film, is formed. When the emitter region 12' is formed on the inside of the edge 11'a of the base region 11', on the other hand, a weld emitter is not shaped. |
