EFFECTS OF MICROGRAVITY ON HG1-XCDXTE (100)CDTE EPITAXY BY CVT UNDER TRANSIENT GROWTH-CONDITIONS

Transient epitaxial growth experiments of Hg1-xCdxTe on (1 0 0)CdTe su bstrates by chemical vapor transport (CVT),, using HgI2, as a transpor t agent, were performed at normal and reduced gravity during the USML- 2 flight. The carrier mobility at 77 K of the epitaxial layer grown in microgravity is about twice that of the ground specimen. This result is related to the improved compositional uniformity (IR mapping) and s tructural quality (X-ray rocking curves) of the space-grown epitaxial layer and islands relative to ground samples. These observations and t he lower dislocation density of the growth interface in microgravity d emonstrate the: effects of residual convective flow on the transport a nd deposition processes on ground near the solid-vapor interface of th is system in the transient growth regime. (C) 1998 Elsevier Science B. V. All rights reserved.