摘要 |
A heterojunction bipolar transistor (HBT) with improved characteristics is provided. A III-V compound semiconductor having Bi added thereto is used for a base layer of a GaAs-based or InP-based HBT. For example, a GaAs-based HBT is formed by successively stacking a subcollector layer made of n<+>-GaAs, a collector layer made of n<->-GaAs, a base layer made of p<+>-GaAsBi, an emitter layer made of n-InGaP, a first cap layer made of n-GaAs, and a second cap layer made of n<+>-InGaAs on a substrate 1 made of single crystal GaAs.
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