Investigation of Hg1-xCdxTe epitaxial vapor phase growth under isothermal conditions

The Hg1-xCdxTe layers were grown by vapor phase epitaxy on Cd-terminated s111c CdTe single crystal substrates from a HgTe solid source under isothermal conditions in a semi-closed system with controlled Hg vapor pressure. The growth kinetics were investigated in the temperature region from 420 °C to 550 °C with different source to substrate spacings, varying from 1 to 11 mm. It was found that the dependence of the growth rate on temperature could be well described by an Arrhenius type equation with an activation energy of 80 kJ/mol in the investigated temperature interval. The activation energies for the crystallization were the same for all the investigated source to substrate spacing. This activation energy value points to the importance of a solid-state diffusion process in the Hg1-xCdxTe/CdTe epitaxial couple obtained by isothermal growth under the given experimental conditions.