Bipolar transistor with selectively deposited emitter

摘要

A process for forming an emitter for a bipolar junction transistor and a bipolar junction transistor formed according to the process. In one embodiment, the bipolar junction transistor comprises in stacked relation a collector, an intrinsic base, an extrinsic base and an emitter. The emitter is formed by defining an opening in material layers forming the extrinsic base and selectively depositing silicon in the opening. The silicon is doped in situ or by an implant process. In another embodiment lacking an extrinsic base the opening is formed in dielectric material layers overlying the intrinsic base.