Heavily carbon-doped p-type InGaAs grown by gas source molecular beam epitaxy for application to heterojunction bipolar transistors

Abstract

The growth and characteristics of ultrahigh carbon-doped p-type InGaAs lattice matched to InP by gas source molecular beam epitaxy (GSMBE) using carbon tetrabromide (CBr 4) as a doping source was investigated. The effects of growth temperature, group V supply pressure and CBr 4 supply pressure on the composition, hole mobility and concentration of carbon-doped InGaAs were studied. The dependence of hydrogen passivation effect on different AsH 3 supply pressure and different growth temperature were researched. Ultrahigh net hole concentration and room-temperature mobility of 1×10 20 cm −3 and 45 cm 2/V s, respectively, were achieved without any postgrowth annealing. Mobility of the ultrahigh carbon-doped InGaAs using CBr 4 compared favorably to those of CBE grown carbon-doped InGaAs using CBr 4 and molecular beam epitaxy grown beryllium (Be)-doped InGaAs grown at low temperature. The highly carbon-doped InGaAs layers grown by GSMBE using CBr 4 as a doping source were used for the growth of high performance, highly carbon-doped base InP/InGaAs heterojunction bipolar transistor epitaxial layer structures.