| 摘要 |
PURPOSE:To enable to perform an ultra-high speed operation by a method wherein a collector depletion layer containing almost no impurities is provided between a collector layer and a base layer, and an emitter depletion layer containing almost no impurities is formed between the base layer and an emitter layer. CONSTITUTION:An N<+> GaAs collector layer 2 and an i-GaAs collector depletion layer 8 containing almost no impurities are formed on an N<+> GaAs semiconductor substrate 1. Besides, a P<+> GaAs base layer 3, an i-GaAs emitter depletion layer 9 containing almost no impurities, and an N<+> Al0.3Ga0.7As emitter layer 4 having forbidden band width wider than the layer 8 are formed on the layer 8. Then, a collector electrode 5, a base electrode 6 and an emitter electrode 7, which will be ohmic contacted to the collector layer 2, the base layer 3 and the emitter layer 4 respectively, are provided. |
