HETERO-JUNCTION BIPOLAR TRANSISTOR, MANUFACTURING METHOD AND TRANSMITTER/RECEIVER

摘要

PROBLEM TO BE SOLVED: To provide a small size and high performance hetero-junction bipolar transistor whose outer base region can be reduced while its electrical and mechanical properties are not deteriorated. SOLUTION: This hetero-junction bipolar transistor has an emitter layer left near an emitter mesa and on an outer base 122 and consisting of a thin region 120 and a thick region 121 outside the thin region 120. The part of the emitter layer left on the base mesa end is the thick region 121. A base electrode 111a is deposited over the thin region 120 and the thick region 121 on the outer base region 122. With such a construction, base ohmic material is prevented from being diffused into a base layer 104 or into a collector layer 105 on the base mesa end.