Patent ID: 8759880

Claim:
An ultra-high voltage silicon-germanium (SiGe) heterojunction bipolar transistor (HBT), comprising: a P-type substrate with a low dopant concentration; an N-type matching layer, a P-type matching layer and an N− collector region formed on the P-type substrate from the bottom up; two separate field oxide regions in the N− collector region; N+ pseudo buried layers, each under a corresponding one of the field oxide regions and in contact with each of the N-type matching layer, the P-type matching layer and the N− collector region; an N+ collector region between the two field oxide regions, the N+ collector region being formed through the N− collector region and the P-type matching layer and extending into the N-type matching layer; and deep hole electrodes, each in a corresponding one of the field oxide regions and in contact with a corresponding one of the N+ pseudo buried layers.