Heterojunction bipolar transistor and manufacturing method thereof
View Patent ↗In the method for manufacturing a heterojunction bipolar transistor, a collector contact layer, a collector layer, a base layer, a base protection layer, an emitter layer, an emitter contact layer, and a WSi layer are sequentially formed on a substrate. A resist pattern is then formed on the WSi layer, and the WSi layer is patterned by using the resist pattern as a mask. Thereafter, the emitter contact layer and the emitter layer are sequentially removed by ICP (Inductively Coupled Plasma) dry etching by using the resist pattern as a mask.
1. A hetero junction bipolar transistor, comprising:
a collector region layer;
a base layer formed on the collector region layer;
a base protection layer formed on the base layer and containing In;
a base electrode formed on a part of the base protection layer;
an emitter layer formed on another part of the base protection layer and forming a heterojunction with the base layer and containing Ga and As;
an emitter contact layer formed on the emitter layer and containing In; and
an emitter electrode formed above the emitter contact layer and including a WSi layer and other metal layers, wherein
a side surface of the emitter layer is shaped by dry etching and is substantially perpendicular to a top surface of the emitter layer, and a width of the emitter layer is narrower than that of the emitter contact layer.
2. The hetero junction bipolar transistor according to claim 1 , wherein the base protection layer is formed from InGaP.
3. The heterojunction bipolar transistor according to claim 1 , wherein the emitter contact layer is formed from InGaAs.