Heterojunction emitter transistor with saturation drift velocity gradient in base

摘要

A thermionic emission transistor comprising: an emitter region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a collector region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a base region made of a semiconductor material having a second conductivity type opposite to said first conductivity type and a high impurity concentration, that portion of said emitter region located adjacent to said base region having an energy band gap broader than that of the base region, that portion of said base region located adjacent to the emitter region having an impurity concentration of about 3×10. sup.18 cm.sup.-3 or more. Such new transistor has a large transconductance and can be operated with a very large current gain in spite of a very small size of the whole device, and is very suitable for integrated circuit. This transistor requires a small driving power and has a large capability of driving subsequent stages and load, and allows a number of fan-outs is taken and the operating speed is very high.