| 摘要 |
PURPOSE:To obtain the transistor with a low base resistance and a small inert base region by arranging the external base region for the emitter region with the predetermined high accuracy to reduce the base resistance and by equalizing the area of said external base region to a hole of the base contact. CONSTITUTION:Two layers of the SiO2 film and the Si3N4 film covering an N type Si substrate 50 are selectively removed to form the opening 53. Next, an emitter layer 54 and a base layer 55 are formed from the opening 53. After that, selective polycrystalline Si growth is performed to form the overhangs alpha. At this time, the reference values of the SiO2 film 51 and the Si3N4 film 52 are 250Angstrom and 800Angstrom respectively and the thickness of the grown film of the selective growth film 56 is 3,000Angstrom . Accordingly, alpha can be 0.2mum. After that, high- concentration implantation of boron of 5X10<14>-1X10<15>cm<-2> doze quantity is done by ion implantation method and the external base 57 formed by alpha by self- aligning can be obtained. Subsequently, the base contact hole is opened. |
