Carbon-doped InGaP/GaAs/InGaP double heterojunction bipolar transistors

The authors have fabricated the first carbon-doped InGaP/GaAs/InGaP double-heterojunction bipolar transistors which capitalize on the large Delta E/sub v/ of the InGaP/GaAs heterointerface and the high doping concentration in GaAs by carbon atoms. With a 25-AA base setback layer, a current gain of 120 is obtained at J/sub c/ =2 kA/cm/sup 2/. The nonalloy base contact is demonstrated to preserve a current gain of 20 to I/sub c/=10 mu A.