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 (1 11)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 des tabilizing (hot end at bottom) ampoule orientations. The experimental resul ts show the morphological transition of the Hg1-xCdxTe deposition on (111)B CdTe at 545 degrees C from three-dimensional islands to layers within abou t 0.5 and 0.75 h for the growth under vertical stabilizing and destabilizin g conditions, respectively. The combined effects of small convective flow d isturbances on the growth morphology and defect formation are measurable. T he overall trends of the time dependent growth rates and compositions of th e Hg1-xCdxTe epitaxial layers under stabilizing and destabilizing condition s are similar. The systematically higher growth rates of the Hg1-xCdxTe fil ms by about 10% under vertical destabilizing conditions could be influenced by a small convective contribution to the mass transport. The combined res ults show that improved Hg1-xCdxTe epitaxial layers of low twin density on (111)B CdTe substrates can be obtained by CVT under vertical stabilizing co nditions.