Self-aligned emitter-base in advanced BiCMOS technology

摘要

A self-aligned bipolar transistor and method of fabricating the same are disclosed. In an embodiment, a substrate and an intrinsic base are provided, followed by a first oxide layer, and an extrinsic base over the first oxide layer. A first opening is formed, exposing a portion of a surface of the extrinsic base. Sidewall spacers are formed in the first opening, and a self-aligned oxide mask is selectively formed on the exposed surface of the extrinsic base. The spacers are removed, and using the self-aligned oxide mask, the exposed extrinsic base and the first oxide layer are etched to expose the intrinsic base layer, forming a first and a second slot. A silicon layer stripe is selectively grown on the exposed intrinsic and/or extrinsic base layers in each of the first and second slots, substantially filling the respective slot.

主权项

1. A self-aligned bipolar transistor comprising:
an intrinsic base layer disposed above a substrate; an oxide layer disposed above the intrinsic base layer; an extrinsic base layer disposed above the oxide layer; a first slot and a second slot extending vertically through a thickness of each of the extrinsic base layer and the oxide layer, wherein the first slot and the second slot collectively define a perimeter of a substantially annular region; and a selectively grown silicon layer stripe disposed in each of the first slot and the second slot, wherein the selectively grown silicon layer stripe is disposed substantially entirely within the first and the second slots at all times, and at no point overburdens the first slot or the second slot.