Elimination of Burn-in Effect in Metal–Organic Chemical Vapor Deposition Grown InGaP/GaAs Heterojunction Bipolar Transistors by Multistep In situ Annealing

Abstract

The burn-in effect in InGaP/GaAs heterojunction bipolar transistors (HBTs) grown by metal–organic chemical vapor deposition was eliminated by a multistep in situ annealing process. The presence of hydrogen in the HBT base region is the origin of the burn-in effect. An in situ annealing process was conducted during the growth of the emitter cap to reduce the concentration of hydrogen incorporated in the base region. However, diffusion may cause hydrogen to be retrapped in the base and emitter regions during the growth of the residual structure after annealing. In order to eliminate the burn-in effect, a multistep in situ annealing process was evaluated for its ability to overcome the indiffusion of hydrogen. In this investigation, a burn-in effect of less than 5% for metal–organic chemical vapor deposition grown HBTs was achieved without noticeably degrading the device performance by four-step in situ annealing.