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

The possibility of reliable and reproducible p-type doping of (31 l)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~ lOI cmB3 can be obtained under conditions of low As, flux and high ()660 “C) growth temperatures. n-type doping up to a level of 1 x 1019 cmw3 is obtained at low (<500X!) growth temperature and high Asa 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 confirnied 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 /3=240. Doped channel p-type heterojunction field-effect transistors have transconductance g, = 25 mS/mm.