| 摘要 |
PURPOSE:To contrive high speed using a two dimensional electron gas (2DEG) layer by forming a base electrode after forming a high concentration impurity contained layer on a base layer which has a non-doped layer which forms the 2DEG layer. CONSTITUTION:An n type GaAs collector layer 2 is formed on an n<+> type GaAs substrate 1. A non-dope AlGaAs layer 3, an n type AlGaAs layer 4 and a non-dope AlGaAs layer 5 constitute the potential barriers of a collector. An n<+> type emitter layer 9 and a graded AlGaAs emitter side potential barrier layer 8 are selectively etched and part of an n type GaAs layer 7 is exposed, an n<++> type GaAs contact layer 10 is regrown by MBE method, an AuGe/Au film is formed by evaporation and an ohmic base electrode 13 is formed on a base layer consisting of two layers, a non-doped GaAS layer 6 and the n type GaAs layer 7. A 2DEG layer 14 is formed by the electrons supplied from the n type AlGaAs layer 4. |
