Molecular-beam epitaxial growth and characterization of silicon-doped AlGaAs and GaAs on (311)A GaAs substrates and their device applications

Abstract

The possibility of reliable and reproducible p‐type doping of (311)A GaAs by Si during molecular‐beam epitaxial growth and the application of such doping in the realization of high‐performance electronic devices have been investigated. It is seen that p‐type doping upto a free hole concentration of 4×1019 cm−3 can be obtained under conditions of low As4 flux and high (≥660 °C) growth temperatures. n‐type doping up to a level of 1×1019 cm−3 is obtained at low (≤500 °C) growth temperature and high As4 flux. The p‐type doping is extremely reproducible and the incorporation of Si atoms into electrically active As sites is at least 95%. The doping behavior has been studied and confirmed by Raman spectroscopy. n‐p‐n heterojunction bipolar transistors grown by all Si doping exhibit excellent current voltage characteristics and a common emitter current gain β=240. Doped channel p‐type heterojunction field‐effect transistors have transconductance gm=25 mS/mm