BASE PROFILE OF SELF-ALIGNED BIPOLAR TRANSISTORS FOR POWER AMPLIFIER APPLICATIONS

摘要

According to a bipolar transistor structure having a transistor top and a transistor bottom herein, a silicon substrate located at the transistor bottom has a collector region of a first conductivity type. An epitaxial base layer of a second conductivity type overlies, relative to the transistor top and bottom, a portion of the collector region. The epitaxial base layer has a bottom surface on the silicon substrate and a top surface opposite the bottom surface. A top region, relative to the transistor top and bottom, of the epitaxial base layer comprises a concentration of germanium having atomic compositions sufficient to avoid impacting transistor parameters, and sufficient to be resistant to selective chemical etching. A silicon emitter layer of the first conductivity type overlies, relative to the transistor top and bottom, a portion of the epitaxial base layer adjacent to the top surface of the epitaxial base layer.

主权项

1. A bipolar transistor structure having a transistor top and a transistor bottom, said structure comprising:
a silicon substrate located at said transistor bottom and having a collector region of a first conductivity type; an epitaxial base layer of a second conductivity type overlying, relative to said transistor top and said transistor bottom, a portion of said collector region, said epitaxial base layer having a bottom surface on said silicon substrate and a top surface opposite said bottom surface,
a top region, relative to said transistor top and said transistor bottom, of said epitaxial base layer comprising a concentration of germanium having atomic compositions sufficient to avoid impacting transistor parameters, and sufficient to be resistant to selective chemical etching; and a silicon emitter layer of said first conductivity type overlying, relative to said transistor top and said transistor bottom, a portion of said epitaxial base layer adjacent said top surface of said epitaxial base layer.