| 摘要 |
PROBLEM TO BE SOLVED: To improve the rising characteristics of the breakdown voltage and current and voltage characteristics of a heterojunction bipolar transistor containing an InGaP layer in its collector region. SOLUTION: The collector region positioned between a sub-collector layer 4 and a base layer 6 is constituted of three layers of an n-type InGaP collector layer 9, an n-type GaAs collector layer 7, and an n<SP>+</SP>-type GaAs collector layer 8 interposed between the layers 9 and 7. Consequently, the deterioration of the rising characteristics of the current and voltage characteristics of the heterojunction bipolar transistor caused by the interfacial level in the interface between the collector layers 9 and 7 is suppressed. In addition, the electric field strengths of the collector layers 9 and 7 can be adjusted by adjusting the impurity concentration of the collector layer 8. Consequently, the avalanche breakage voltage of the bipolar transistor can be improved. COPYRIGHT: (C)2003,JPO
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