| 摘要 |
PROBLEM TO BE SOLVED: To increase reliability without performance loss. SOLUTION: A hetero-junction bipolar transistor has such a structure that a collector contact layer 2 is formed on a GaAs substrate 1 and a collector layer 3 is formed on the collector contact layer 2. Collector electrodes 16 and a base layer 4 are formed on the collector layer 3, and base electrodes 25 and a first emitter layer 5 formed of a material having band gap energy larger than that of the base layer are formed on the base layer 4. A second emitter layer 6 is formed on the first emitter layer 5, an emitter contact layer 7 is formed on the second emitter layer 6, and an emitter electrode 11 is formed on the emitter contact layer 7. The base electrode 25 is so formed as to overlap a ridge 14 formed of a peripheral part of the first emitter layer 5. COPYRIGHT: (C)2003,JPO
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