Transient behavior of Hg1-xCdxTe film growth on (111)B CdTe substrates by chemical vapor transport

As part of a systematic investigation of the effects of substrate surfaces on epitaxial growth, the transient behavior of Hg1-xCdxTe film growth on (111)B CdTe by chemical vapor transport (CVT) has been studied as a function of growth time under vertical stabilizing (hot end on top) and vertical destabilizing (hot end at bottom) ampoule orientations. The experimental results show the morphological transition of the Hg1-xCdxTe deposition on (111)B CdTe at 545 degrees C from three-dimensional islands to layers within about 0.5 and 0.75 h for the growth under vertical stabilizing and destabilizing conditions, respectively. The combined effects of small convective flow disturbances on the growth morphology and defect formation are measurable. The overall trends of the time dependent growth rates and compositions of the Hg1-xCdxTe epitaxial layers under stabilizing and destabilizing conditions are similar. The systematically higher growth rates of the Hg1-xCdxTe films by about 10% under vertical destabilizing conditions could be influenced by a small convective contribution to the mass transport. The combined results show that improved Hg1-xCdxTe epitaxial layers of low twin density on (111)B CdTe substrates can be obtained by CVT under vertical stabilizing conditions.