Patent ID: 8557670

Claim:
A method of forming a semiconductor structure including a bipolar junction transistor (BJT), said method comprising: providing a substrate including a semiconductor portion comprising a first semiconductor material having a first band gap and having a doping of a first conductivity type; converting a region of said semiconductor portion into an emitter region by introducing dopants of a second conductivity type that is the opposite of said first conductivity type into said region of said semiconductor portion, wherein a remaining region of said semiconductor portion constitutes a base region that laterally contacts said emitter region; converting another region of said semiconductor portion into a collector portion by introducing dopants of said second conductivity type into said another region of said semiconductor portion simultaneously with said conversion of said region into said emitter region, wherein said collector region laterally contacts said base region upon formation; and depositing an emitter contact region comprising a portion of a second semiconductor material having a second band gap that is greater than said first band gap and having a doping of said second conductivity type directly on said emitter region.