InP/InGaAs double-heterojunction bipolar transistors grown on [100] Si by metalorganic chemical vapor deposition

Abstract

The authors report the successful fabrication of InP/InGaAs double-heterojunction bipolar transistors (DHBTs) grown by metalorganic chemical vapor deposition (MOCVD) on Si substrates. The Si substrates used were p-type (boron doped) FZ grown wafers with a resistivity of 5000 Omega *cm, oriented 2 degrees off the [100] plane toward the [110] direction. Epitaxial layers for DHBTs were grown on the Si substrate with a thin GaAs buffer layer. A two-step growth process was applied for the InP layers on GaAs-on-Si wafers. The transistors exhibit high current gains over 200, which is comparable to those in transistors grown on InP substrates. The dislocations are found to increase the recombination current very little in the neutral base region, but increase in generation-recombination current at the emitter-base interface. >