InAlAs/InGaAsSb/InGaAs double heterojunction bipolar transistors with high current gain and low base sheet resistance

The proposed InAlAs/InGaAsSb/InGaAs double heterojunction bipolar transistors (DHBTs) exhibit a rather high current gain despite the use of a highly doped and thick InGaAsSb base layer, indicating that a high minority carrier lifetime exists in the InGaAsSb material. A high current gain over sheet resistance ratio, low cross-over current and a wide constant current gain range have been achieved, suggesting that the novel InAlAs/InGaAsSb/InGaAs DHBTs are grown with a high quality InGaAsSb base layer.