PARATYPE DOPING OF METALORGANIC CHEMICAL VAPOR DEPOSITION-GROWN HGCDTE BY ARSENIC AND ANTIMONY

Extensive data are presented on the arsenic doping characteristics of Hg1-xCdxTe layers grown by metalorganic chemical vapor deposition using the dopant source tertiarybutylarsine (TBAs). The incorporation of arsenic in the layer is proportional to the II-VI alkyl ratio during TBAs injection. High arsenic concentrations significantly increase the layer dislocation density. Acceptor activation efficiency (taken to be the 77 K carrier concentration divided by the layer arsenic concentration) is approximately 50% for a wide range of conditions, but decreases for arsenic concentrations approaching 10(18) cm-3. For arsenic concentrations below low-10(17) cm-3, the 77 K carrier concentration is stable even for sample annealing at 400-degrees-C on the Te-rich side of the phase boundary. 77 K hole mobility strongly depends on composition x. Variable temperature Hall effect measurements show that one layer exhibits the expected carrier freeze-out with an ionization energy of 4.8 meV, but three other layers exhibit a much smaller degree of freeze-out. Preliminary results using the dopant source triisopropylantimony are also presented.