DIRECTED EPITAXIAL HETEROJUNCTION BIPOLAR TRANSISTOR

摘要

A directed epitaxial heterojunction bipolar transistor (HBT) structure is directly or indirectly formed on a GaAs substrate that is formed by a (100) face towards a (111)B face with an angle of inclination between 0.6° and 25°, and includes a sub-collector layer, a collector, a base layer, an emitter layer, an emitter cap layer and an ohmic contact layer, which are sequentially formed on the substrate. A tunnel collector layer formed by InGaP or InGaAsP is provided between the collector layer and the base layer. Since an epitaxial process is performed on the substrate from a (100) face towards a (111)B face with an angle of inclination between 0.6° and 25°, indium and gallium contained in InGaP or InGaAsP are affected by the ordering effect such that InGaP or InGaAsP used in the emitter layer and/or the tunnel collector layer has a higher electron affinity or a smaller bandgap.

主权项

1. A directed epitaxial heterojunction bipolar transistor (HBT) structure, comprising:
a sub-collector layer formed by N-type group III-V semiconductors and stacked on a substrate, wherein the substrate is formed by GaAs that is formed by a (100) face towards a (111)B face with an angle of inclination between 0.6° and 25°; a collector layer stacked on the sub-collector layer and formed by N-type group semiconductors; a base layer stacked on the collector layer and formed by P-type group semiconductors; an emitter layer stacked on the base layer and formed by N-type InGaP or InGaAsP; an emitter cap layer stacked on the emitter layer and formed by N-type group III-V semiconductors; and an ohmic contact layer stacked on the emitter cap layer and formed by N-type group III-V semiconductors.