INVESTIGATION OF POLYCRYSTALLINE CDTE THIN-FILMS DEPOSITED BY PHYSICAL VAPOR-DEPOSITION, CLOSE-SPACED SUBLIMATION, AND SPUTTERING

CdTe thin films, deposited on different substrate structures by physic al vapor deposition, sputtering, and close-spaced sublimation, have be en treated with CdCl2 at several temperatures. The morphology of the f ilms has been studied by atomic force microscopy, and the observations were correlated to results obtained from x-ray diffraction, cathodolu minescence, and minority-carrier lifetime measurements. The samples tr eated at 400 degrees C resulted in the best device-quality films, inde pendent of deposition method and underlying substrate structure. For t he first time, a nanograin structure was observed in CdTe sputtered sa mples. (C) 1995 American Vacuum Society.