InGaP/GaAs heterojunction bipolar transistor grown on a semi-insulating InGaP buffer layer

To improve electrical isolation and simplify the heterojunction bipolar transistor (HBT) fabrication process, a semi-insulating InGaP buffer layer has been employed in an InGaP/GaAs HBT. Data is presented that demonstrates this buffer layer serves as an excellent isolation material. In addition, high-frequency HBT's have been fabricated and characterized to show that the buffer layer does not degrade device performance.