High-f/sub max/ InP/InGaAs HBTs with extrinsic base layers selectively grown by MOCVD

Abstract

Summary form only given. A selectively-grown heavily-doped extrinsic-base structure is very effective for reducing the base resistance of heterojunction bipolar transistors (HBTs), and has been applied to AlGaAs/lnGaAs(GaAs) HBTs with GaAs extrinsic-base layers. For InGaAs layers, low growth temperatures (T/spl les/450/spl deg/C) are necessary for achieving a heavy p-type doping. However, low-temperature selective MOCVD of InGaAs was difficult, so good selectivity had been reported only at relatively high growth temperatures (T /spl ges/600/spl deg/C). We have demonstrated perfect selective growth of InGaAs layers at 400/spl deg/C with a high-speed rotation susceptor. In this paper, we report the first successful fabrication of an InP/InGaAs HBT with a selectively grown extrinsic base layer using this technique.