Metalorganic chemical vapor deposition growth of Cd1−yZnyTe epitaxial layers on GaAs and GaAs/Si substrates

As a step toward growth of HgCdTe on GaAs and GaAs/Si substrates, Cd1–yZnyTe buffer layers were grown on these substrates. A conventional pyrolytic process at relatively high temperature (441 °C) was used. Epitaxial growth on GaAs was achieved for all alloy compositions, 0≤y≤1. The solid–vapor distribution curve for alloy deposition was determined experimentally for one particular set of deposition parameters, and compared with a thermodynamic model. Deposit uniformity was also studied experimentally and compared with a model incorporating coupled fluid dynamics and mass transport (but not chemical kinetics) with realistic reactor boundary conditions and thermal effects. Epitaxial growth on the GaAs(123) substrates orientation was studied by x‐ray techniques. Cd1–yZnyTe epitaxial layers grown on these substrates were tilted with respect to the substrate toward 〈111〉, about a 〈121〉 axis. The degree of tilt depended on the alloy composition y, ranging from 1.7° for y=1 to 3.2° for y=0. These results are co...