Deposition of CdTe Epitaxial Layers on GaAs Substrates Using Dimethyl Cadmium and Methylallyl Tellurium

The effect of deposition conditions on the growth rate, crystal quality, surface morphology and concentration of growth defects of CdTe epitaxial layers obtained by MOCVD on GaAs (310), (100), (111) B substrates using dimethylcadmium and methylallyltellurium (MATe) was studied.The growth rate of CdTe layers under the studied conditions varied from 0.6 to 2.0 μm/h, and the apparent activation energy of the growth process at 300–350°C was in the range of 45.2–54.0 kJ/mol. It is suggested that the limiting stage of deposition in this temperature range is the adsorption stage of reagents (primarily MATe) on the surface. CdTe (100) layers grown at 300–350°C had the best crystal quality. The smoothest and most mirror-like surfaces were found in CdTe (100) and (111)B layers grown at temperatures of 330–350 and 330–370°C, respectively. The conditions for obtaining CdTe (100) layers with a concentration of growth defects (10–20 microns in size) on the surface of ≤150 cm have been established.