Patent ID: 8927379
Filing Date: 2015-01-06
Classification: H01L

Abstract:
1. A method of forming a semiconductor device comprising: providing a self-aligned sacrificial emitter process pedestal stack on a wafer; growing a SiGe layer on said wafer; forming a trench in said wafer, said trench circumscribing said pedestal stack and defining an intrinsic base of a bipolar transistor; performing a selective epitaxial growth process to form an extrinsic base at two regions around said stack and a bridge over said trench, said bridge connecting said two regions, said selective epitaxial growth process ensuring substantially no growth originates from a bottom of said trench; forming an emitter window in said pedestal stack; performing in-situ doped emitter deposition in said emitter window; and performing photolithographic deposition and etching to define an emitter of said bipolar transistor.