| 摘要 |
<p>For improvement in operation speed, there is provided a heterojunction bipolar transistor comprising, a) an emitter region (27) formed of a first semiconductor material of a first conductivity type, b) a base region (24) formed of a second semiconductor material of a second conductivity type opposite to the first conductivity type and forming a first junction together with the emitter region, and c) a collector region (23) formed of a third semiconductor material of the first conductivity type and forming a second junction together with the base region, the heterojunction bipolar transistor has a plurality of abrupt potential discontinuities including first and second abrupt potential discontinuities produced in succession to provide kinetic energies to a carrier injected from the emitter region, respectively, and the first abrupt potential discontinuity is produced at one of the first and second junctions, thereby allowing the carrier to move over a distance longer than a linear free path of the carrier in the ballistic manner.</p> |
