US Patent 7202515 Heterojunction bipolar transistor and manufacturing method thereof

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.