InGaP/GaAs heterojunction bipolar transistor grown on Si substrate with SiGe graded buffer layer

What is believed to be the first InGaP/GaAs heterojunction bipolar transistor grown on SiGe/Si substrate is reported. The collector-emitter offset voltage and the knee voltage of the device are ~150 mV and <1 V, respectively. The maximum gain of the device is ~25 at collector current of ~100 mA. The collector and base ideality factor are ~1.01 and ~1.4, respectively. These results show the good potential for integrating the InGaP/GaAs heterojunction bipolar transistor on Si substrate using the compositionally graded SiGe buffer layer approach.