LOCAL COLLECTOR IMPLANT STRUCTURE FOR HETEROJUNCTION BIPOLAR TRANSISTORS AND METHOD OF FORMING THE SAME

摘要

A bipolar transistor structure (600) includes an intrinsic base layer (106) formed over a collector layer (104), an emitter (110) formed over the intrinsic base layer, and an extrinsic base layer (108) formed over the intrinsic layer and adjacent the emitter. A ring shaped collector implant structure (604) is formed within an upper portion of the collector layer, wherein the ring shaped collector implant structure is disposed so as to be aligned beneath a peritneter portion of the emitter.