| 摘要 |
PURPOSE:To increase the current amplification factor by forming a one conductive type compound semiconductor collector layer, an undoped compound semiconductor base layer, and one conductive type compound semiconductor energy band gap layer, thereby operating at a high speed. CONSTITUTION:When a reference bias voltage is applied, electrons (e) implanted from an N-type AlGaAs emitter layer 16 through an I-type AlGaAs emitter layer 15 to an I-type GaAs base layer 14 are moved variously to arrive at an N-type GaAs collector layer 13. In this case, since the layer 14 is of I-type, i.e., undoped, Coulomb scattering due to the impurity does not occur, and the electrons (e) accordingly arrive at the layer 13 at a high speed. If the electrons (e) stall during moving in the layer 14 to fall in the bottom Ec of the conduction band, when they have passed secondary electron gas layer 21, they can arrive at the layer 13. |
