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US 7,256,434 B2Granted
Heterojunction bipolar transistor and method for manufacturing the same, and power amplifier using the same
AssigneeRenesas Technology Corp.
InventorsIsao Ohbu, Chushiro Kusano, Yasunari Umemoto, Atsushi Kurokawa
Life of this patent
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Abstract
A heterojunction bipolar transistor with InGaP as the emitter layer and capable of both reliable electrical conduction and thermal stability wherein a GaAs layer is inserted between the InGaP emitter layer and AlGaAs ballast resistance layer, to prevent holes reverse-injected from the base layer from diffusing and reaching the AlGaAs ballast resistance layer.
Claims4
A heterojunction bipolar transistor with a sequentially formed structure comprised at least of an InGaP emitter layer and a base layer forming a heterojunction together with the InGaP emitter layer on one side;
- and a GaAs layer and an AlGaAs ballast resistance layer on the other side,
- wherein the heterojunction bipolar transistor includes a voltage limiter protection circuit, and
- wherein an anode of the protection circuit is connected to a collector electrode, and a cathode of the protection circuit is connected to an emitter electrode.
Dependencies are inferred from the claim text.