SELECTIVE MOLECULAR-BEAM EPITAXY FOR INTEGRATED NPN PNP HETEROJUNCTION BIPOLAR-TRANSISTOR APPLICATIONS

We have developed a selective molecular-beam epitaxy (MBE) growth process for the production of complementary npn and pnp heterojunction bipolar transistors (HBTs) on the same GaAs substrate. The resulting devices have excellent dc and microwave characteristics, with no degradation observed due to the additional growth and processing steps required to monolithically integrate npn and pnp HBTs. We believe the ability to fabricate high-quality complementary HBT devices and circuits will greatly expand the application base of MBE-grown heterojunction bipolar transistors.