LOW-TEMPERATURE GROWTH OF (100) HGCDTE LAYERS WITH DTBTE IN METALORGANIC VAPOR-PHASE EPITAXY

Growth characteristics of (100) HgCdTe (MCT) layers by MOVPE at low te mperature of 275 degrees C were studied using ditertiarybutyltelluride as a tellurium precursor. Growths were conducted in a vertical narrow -spacing growth cell at atmospheric pressure. Cd composition of MCT la yers were controlled from 0 to 0.98 using dimethylcadmium (DMCd) flow. The growth rate was constant for increase of DMCd flow. During the gr owth, Cd was incorporated preferentially into the MCT layers. Enhancem ent of Cd incorporation in the presence of Hg was also observed. Cryst al quality and electrical properties were also evaluated, which showed that high quality MCT layers can be grown at 275 degrees C. Strain in CdTe layers grown at 425 and 275 degrees C was also evaluated. Lattic e parameter of layers grown at 425 degrees C approached bulk value at thickness of 5 mu m, while layers grown at 275 degrees C relaxed at 1 mu m The rapid strain relaxation of layers grown at 275 degrees C was considered due to the layer growth on the strain relaxed buffer layer. The effect of the thermal stress on the relaxation of CdTe lattice st rain was also discussed.