IMPURITIES AND METAL ORGANIC CHEMICAL-VAPOR DEPOSITION GROWTH OF MERCURY CADMIUM TELLURIDE

The doping behavior of indium and iodine have been investigated for mercury cadmium telluride (MCT, Hg1-x Cd(x) Te) layers deposited by the interdiffused multilayer process procedure at 400-degrees-C using diethyl tellurium and dimethyl cadmium. Trimethyl indium and solid iodine were used as dopant sources. Both elements exhibited donor behavior under the conditions employed. Secondary ion mass spectrometry profile analysis was used to demonstrate that indium required a relatively long period during growth to attain an equilibrium concentration in the layer; in addition a significant reactor system memory was observed allied to a relatively fast diffusion rate. Iodine showed encouraging dopant properties at low concentration levels, the chemical concentration of iodine was in good agreement with the free donor level from Hall measurements. The advantage and applicability of each of the three chemical analysis procedures used in this work are discussed together with comments on the residual impurity content and electrical properties of undoped layers.