| 摘要 |
PURPOSE:To obtain a bipolar transistor which has high speed, large current amplification factor and low rising voltage in base and emitter direction by forming a thin semicondctor film of large charge mobility and small energy gap as compared with a semiconductor of emitter and collector regions as a base region. CONSTITUTION:An N<+> type buried region 21 is formed in emitter and collector regions on a P type Si substrate 20. An Si epitaxial layer 22 and an interelement separating SiO2 region 23 are formed thereon. An SiO2 film 24 is formed, and the films 24 of the emitter and base regions are removed. An SiO2 insulating film 25 and an Mo conductor film 26 are formed. The films 25, 26 of the emitter forming region are removed to expose the substrate 20. Then, a P type Ge layer 28 and N<+> type Si layer 29 having small energy gap and large charge mobility than Si are formed by an MBE method, polycrystalline Ge layer 30 and Si layer 31 are removed on the films 24, 26, SiO2 film 33 is formed, and base electrode wirings 34, emitter electrode wirings 35 and collector electrode wirings 36 are formed. |
