Epitaxial growth of CdTe on (211) silicon mesas formed by deep reactive ion etching

By patterning a (211) Si substrate wafer into mesas and depositing CdTe onto this substrate by molecular beam epitaxy (MBE), we achieved the removal of nearly all threading dislocations from the epilayer. Faceting of mesa surfaces is observed and characterized. Deposition of CdTe on mesa sidewalls nucleates stacking faults along the (111) planes, which result in nonradiative carrier recombination. The density of these stacking faults can be reduced if care is taken to align the molecular beams from the effusion cells with particular crystallographic directions of the substrate.