Patent ID: 8866189
Filing Date: 2014-10-21
Classification: H01L

Abstract:
1. A silicon-germanium (SiGe) heterojunction bipolar transistor (HBT), comprising: a substrate; two field oxide regions formed in the substrate; two pseudo buried layers, each being formed under a corresponding one of the field oxide regions; a collector region formed between the field oxide regions, each side of the collector region laterally extending under a corresponding one of the field oxide regions and being connected with a corresponding one of the pseudo buried layers; a matching layer formed under both the pseudo buried layers and the collector region; and a deep hole electrode, formed in each of the field oxide regions and being connected to the corresponding one of the pseudo buried layers for picking up the collector region, wherein both of the pseudo buried layers have a doping type same with that of the collector region and have a doping concentration higher than that of the collector region; and the matching layer has a doping type opposite to that of the collector region.