| 摘要 |
PURPOSE:To increase the capacitance of an emitter and switching-speed by reducing the area of an emitter-base junction and the finger width of the emitter. CONSTITUTION:Multilayer semiconductor layers are formed onto a semi- insulating substrate as semiconductor layers, which contain at least one conduction type collector layer and on which a reverse conduction type base region is shaped, or reverse conduction type base layers. An insulating film coating the whole surface is formed, and an opening from which a reverse conduction type base region or the partial surface of the reverse conduction type base layer is exposed selectively is shaped. One conduction type emitter layer having a band gap wider than the reverse conduction type base region or that of the reverse conduction type base layer is formed. Accordingly, the area of an emitter-base junction or the area of a base-collector junction can be reduced, thus lowering emitter capacitance and collector capacitance. |
