Patent ID: 6730986
Filing Date: 2004-05-04
Classification: H01L

Abstract:
A bipolar junction transistor, comprising:an intrinsic collector region of first conductivity type in a semiconductor substrate; a trench in said substrate, adjacent said intrinsic collector region; a base electrode of second conductivity type in the semiconductor substrate, said base electrode comprising a trench-based electrode portion that extends in said trench and a lateral base electrode extension that extends outside said trench; an extrinsic base region of second conductivity type that is self-aligned and electrically connected to said lateral base electrode extension and forms a P-N rectifying junction with said intrinsic collector region; an intrinsic base region of second conductivity type that is self-aligned to said lateral base electrode extension, has a lower second conductivity type doping concentration therein relative to said extrinsic base region and forms a P-N rectifying junction with said intrinsic collector region; a trench insulating layer that lines a bottom and sidewalls of said trench and prevents direct electrical contact between the trench-based electrode portion of said base electrode and said extrinsic base region by blocking charge transfer across the sidewalls of said trench; and an emitter region of first conductivity type that forms a P-N rectifying junction with said intrinsic base region.