Control of acceptor doping in MOCVD HgCdTe epilayers

摘要

The acceptor doping of mercury cadmium telluride (HgCdTe) layers grown by MOCVD are investigated. (111 )HgCdTe layers were grown on (100)GaAs substrates at 350℃ using horizontal reactor and interdiffused multilayer process (IMP). TDMAAs and AsH3 were alternatively used as effective p-type doping precursors. Incorporation and activation rates of arsenic have been studied. Over a wide range of Hg_(1-x)Cd_xTe compositions (0.17 < x < 0.4), arsenic doping concentration in the range from 5 x10~(15) cm~(-3) to 5 x10~(17) cm~(-3) was obtained without postgrowth annealing. The electrical and chemical properties of epitaxial layers are specified by measurements of SIMS profiles, Hall effect and minority carrier lifetimes. It is confirmed that the Auger-7 mechanism has decisive influence on carrier lifetime in p-type HgCdTe epilayers.