Patent ID: 7851319

Claim:
A method for preparing a non-self-aligned heterojunction bipolar transistor comprising in uninterrupted sequence: a) preparing a patterned emitter metal on an emitter epi layer of a HBT epi structure on a substrate; b) preparing an emitter epitaxy disposed exclusively below the emitter metal; c) depositing a base metal layer on an exposed top surface; d) applying a resist on the base metal layer; e) applying a lithography mask covering a peripheral edge of the emitter epitaxy and the emitter metal with a width P D and leaving a pattern according to the lithography mask in the resist; f) removing portions of the base metal layer not covered by resist; and g) removing remaining resist, h) the base metal being spaced from the emitter epitaxy and the emitter metal by a distance X D , wherein the distance X D ranges from 0.05 μm to 0.7 μm.