Patent ID: 7285457
Filing Date: 2007-10-23
Classification: H01L

Abstract:
1. A method for manufacturing a heterojunction bipolar transistor, comprising the steps of: (a) sequentially forming a collector layer, a base layer, a base protection layer, an emitter layer, an emitter contact layer, and a first metal film on a substrate; (b) after the step (a), forming a first resist on a part of the first metal film; (c) after the step (b), patterning the first metal film by using the first resist as a mask; (d) after the step (c), conducting dry etching at a higher selectivity of the emitter layer over the emitter contact layer until the base protection layer is exposed by using the first resist layer as a mask, in order to make a width of the emitter layer narrower than that of the emitter contact layer; (e) after the step (d), removing the first resist to expose the first metal film; and (f) after the step (e), depositing a second metal film after forming a second resist that exposes the first metal film and the exposed part of the base protection layer, and removing the second resist and a part of the second metal film which is located on the second resist.