| 摘要 |
PURPOSE:To manufacture the IC in a double base structure without increasing phototype processes by selectively oxidizing a surface of a polysilicon film as an emitter and collector electrode wirings and forming a high density base electrode taking-out region of an external base with the oxidized film as a mask. CONSTITUTION:Each junction surface of an n type epitaxial layer 3 formed on a p type silicon semiconductor substrate 1 and a base layer 6 is covered with two layers formed by the oxidized film 102 and nitriding film 201 as an acid-proof film, the emitter layer 7 is formed in the base layer 6 by the impurity diffusion from the polysilicon layer 31 doped with the impurity in high density and at the same time, a collector electrode taking-out region 8 is formed in the epitaxial layer 3. A layer 301 is selectively etched to form the emitter and collector electrode wirings 302, 303. Further, oxide films 104, 105 are formed on the surfaces of the wirings 302, 303 with the nitriding film 201 as the mask and after an exposed part of the nitriding film 201 having been removed, the high density impurity are diffused to form the base electrode taking out region with the oxide films 104, 105 as the masks. |
