Threading dislocation removal from the near-surface region of epitaxial cadmium telluride on silicon by lithographic patterning of the substrate

(211) oriented silicon substrates were patterned and etched to give mesas of various sizes and shapes. Cadmium telluride epitaxial layers were deposited on the patterned substrates by molecular beam epitaxy (MBE). Dislocation termini in the epilayer were found to be concentrated in the trenches that formed the mesa boundaries. Mesa sizes up to 17 µm were found to be nearly free of threading dislocation termini. Threading dislocation termini are observed to congregate in lines parallel to the crystallographic directions. Evidence of subsurface, horizontal dislocations running through the mesa is given. [PUBLICATION ABSTRACT]