Epitaxial wafer for heterojunction bipolar transistor and heterojunction bipolar transistor
AssigneeSumitomo Chemical Company, Limited
InventorsShinjiro Fujio, Takeshi Meguro
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Abstract
An epitaxial wafer for a heterojunction bipolar transistor and a heterojunction bipolar transistor that are capable of further reducing a turn-on voltage are provided. An epitaxial wafer for a heterojunction bipolar transistor includes a collector layer made of GaAs, a base layer formed on the collector layer and made of InGaAs, and an emitter layer formed on the base layer and made of InGaP, and the base layer has an In composition that decreases from the emitter layer side toward the collector layer side.
Claims14
An epitaxial wafer for a heterojunction bipolar transistor, the epitaxial wafer comprising:
- a collector layer made of GaAs;
- a base layer formed on the collector layer and made of InGaAs;
- and
- an emitter layer formed on the base layer and made of InGaP, and
- the base layer having an In composition that decreases from the emitter layer toward the collector layer, a difference between a maximum value and a minimum value of the In composition of the base layer is equal to or less than 0.06.
Dependencies are inferred from the claim text.