Semiconductor device and fabrication method thereof

摘要

The present invention discloses a process of fabricating a semiconductor device comprising the steps of: forming a collector layer of a first conductivity type at a portion of a surface of a semiconductor substrate; forming a collector opening portion in a first insulating layer formed on the semiconductor substrate; epitaxially growing, on the semiconductor substrate of the collector opening portion, a semiconductor layer including a layer of a second conductivity type constituting a base layer; sequentially layering, on the semiconductor substrate, an etching stopper layer against dry etching and a masking layer against wet etching; exposing a part of the etching stopper layer by removing a part of the masking layer by means of dry etching; and by subjecting the exposed etching stopper layer to a wet etching treatment using the remaining masking layer as a mask, forming a base junction opening portion through the etching stopper layer and the masking layer.