BIPOLAR TRANSISTOR AND METHOD OF MANUFACTURE THEREOF

摘要

A spacer layer (151) of SiGe, a graded base layer (152) of boron-containing SiGe, and a silicon cap layer (153) are epitaxially grown in sequence on a collector layer (102) of a silicon substrate. On the silicon cap layer (153) are formed a second deposited oxide (112) with a base opening (118) and a P<+> polysilicon layer (115) filled in the base opening to form an emitter contact, and phosphorus is diffused in the silicon cap layer (153) to form a diffused emitter layer (153a). In growing the silicon cap layer (153), in-situ doping is used so that boron may be present only in upper portions. As a result, the width of a depletion layer (154) is reduced, thus reducing recombination current and improving the linearity of a current characteristic.