| 摘要 |
PURPOSE:To operate the transistor rapidly, by forming two-dimentional electrons between a first conductor layer containing no impurity and a second conductive layer having a wider band gap than that of the first conductive layer and containing an n type impurity, for conducting electricity to an emitter or a collector. CONSTITUTION:An undoped GaAs layer 11a, n<+>-AlGaAs layer 12, n-AlGaAs layer 13, p<+>-GaAs layer 14, n-GaAs layer 15 and an n<+>-GaAs layer 16 are grown by the MBE process or the like on a semi-insulating substrate 11, successively in that order. The layers are formed in stepped form by the etching or the like, acording to the element pattern. An p<+> outer base layer 17 or an n<+> collector layer 18 is formed by the ion implantation or the like, and electrodes are formed. Thus, the structure with the collector at the top is provided, and therefore the bulk emitter resistance is substantially reduced by two-dimentional electron gas. |
