Patent ID: 9048280
Filing Date: 2015-06-02
Classification: H01L

Abstract:
1. A method of fabricating a heterojunction bipolar transistor (HBT) structure, comprising: forming a collector and a base in a substrate, wherein said substrate comprises a buried insulator layer, wherein said collector comprises a first single crystalline germanium portion having a doping of a first conductivity type, and said base comprises a second single crystalline germanium portion epitaxially aligned to said collector and has a doping of a second conductivity type that is the opposite of said first conductivity type; forming deep trench isolation structures, wherein said deep trench isolation structures extend from a top surface of said substrate, through said collector to a depth beneath a top surface of said buried insulator layer; and forming an emitter comprising a polycrystalline silicon portion having a doping of said first conductivity type directly on said base.