Patent ID: 8810005

Claim:
A bipolar device comprising: an intrinsic base layer comprising: a monocrystalline section having a first center portion and a first edge portion positioned laterally adjacent to said first center portion; and a polycrystalline section positioned laterally adjacent to said first edge portion; a dielectric layer on said polycrystalline section; a semiconductor layer on said first center portion and having a second center portion, a second edge portion positioned laterally adjacent to said second center portion and a vertical extension offset from said second edge portion; and multiple extrinsic base layers comprising: a first extrinsic base layer on said dielectric layer and further extending laterally over top surfaces of said first edge portion and said second edge portion to said vertical extension; and a second extrinsic base layer on said first extrinsic base layer and extending laterally to said vertical extension such that said first extrinsic base layer and said second extrinsic base layer have vertically aligned sidewalls, said second edge portion and said vertical extension of said semiconductor layer being an entirely monocrystalline link-up region between said intrinsic base layer and said multiple extrinsic base layers.