Heterojunction compound bipolar transistor

Abstract

Abstract PURPOSE:To improve an emitter injection efficiency by making the emitter region of a heterojunction compound bipolar transistor a superlattice. CONSTITUTION:A heterojunction compound bipolar transistor comprises a P-type base region 2 of GaAs doped with a low level acceptor impurity, an n-type collector region 3 of GaAs doped with a medium level donor impurity, and an emitter region 5 constituted by a superstructure comprising an n-type GaAs layer doped with a high level donor impurity and an undoped layer of AlAs containing no impurity, all on a highly resistant substrate. In a condition wherein no bias is applied between an emitter and a base, the whole electrons (e) are present in the n-type GaAs layer of the impurity doped layer. When forward biased, the total potential barrier on the side of the emitter is lowered. The electrons (e) sequentially moves into the adjacent n-type GaAs layer as shown in a full line (d).

Inventors

• 👤 Kazunao Tokunaga
• 👤 徳永　一直

Bibliographic Details