Patent ID: 6528862
Filing Date: 2003-03-04
Classification: H01L

Abstract:
A bipolar transistor comprising:a first epitaxial layer of a first conductivity type; a second epitaxial layer that contacts the first epitaxial layer, the second epitaxial layer having: a first doped region of the first conductivity type, a second doped region of a second conductivity type formed below the first doped region, the second doped region having a lightly-doped region adjacent to the first doped region, and a heavily-doped region adjacent to the lightly-doped region, the lightly-doped region having a top surface, the heavily-doped region having a peak dopant concentration at a peak position within the heavily-doped region, a depletion region between the first doped region and the second doped region; and a silicon germanium (SiGe) region having a top surface, the top surface being spaced apart from the depletion region; and a conductive region formed to contact the first doped region.