| 摘要 |
PURPOSE:To improve an implantation efficiency to an emitter and a transfer factor to a base of a reversing transistor for switching by forming the effective emitter of the reversing transistor for switching from a material, a band-gap thereof is wider than that of the base. CONSTITUTION:A p type GaAs semiconductor layer 13 is hetero-epitaxial grown on an n<+> type GaAlAs semiconductor layer 12 through a molecular-beam epitaxial growth method, and an n type GaAs (or GaAlAs) semiconductor layer 14 as a collector and an n<+> type GaAs (or GaAlAs) semiconductor layer 15 are also hetero-epitaxial grown continuously on the layer 13. A GaAlAs semiconductor is used as the semiconductor layer 12 because its band-gap is made wider than that of the semiconductor layer 13 as the base. Consequently, epitaxial growth layers are used extending over all of the emitter, base and collector of the reversing transistor. The band-gap of the emitter is made wider than that of the base, and the transistor inclines toward the collector from the emitter. Accordingly, electrons as a small number of carriers easily enter into the base from the emitter, but holes are difficult to enter into the emitter from the base, and a drift field is generated to electrons being implanted, thus improving the transfer factor in the base of electrons, then operating the circuit at high speed. |
