| 摘要 |
A heterojunction bipolar transistor, having a structure in which a subcollector layer (10) of a first conductive type having a higher doping concentration than a collector layer, the collector layer (9a) of the first conductive type, a base layer (7) of the second conductive type, and an emitter layer (6) of the first conductive type are deposited, in order, on a semi-insulating semiconductor substrate (11), and in which a hole barrier layer (8a) of semiconductor material with a band gap wider than that of the base layer is inserted between the base layer (7) and the collector layer (9a), so as to be in direct contact with the base layer (7). <IMAGE> |
