| 摘要 |
PURPOSE:To improve a device in its performance characteristics by a method wherein a collector barrier is constituted of a superlatice for an improved transfer ratio or current amplification factor. CONSTITUTION:A collector barrier is built of a superlattice in this design. In an appropriately designed superlattice, an auxiliary conduction band is gener ated, wherein electrons may be in presence, under a normal conduction band. In a collector barrier 12, there exist auxiliary conduction bands 1 and 2. Upon application of bias voltages VBE and VCB, those equipped with energy higher than that of the collector barrier 12, out of electrons 3 that have tunneled through an emitter barrier 14, arrive at a collector 16 and, as for those equipped with energy lower than that of the collector barrier 12, they can also arrive at the collector 16 though only after passing through the auxiliary conduction band 1 or 2. In this way, probability is lowered of electrons' being stopped by the collector barrier 12, which results in an increased transfer ratio or current amplification factor. |
