EFFECT OF THE SUBSTRATE NATURE ON THE STRUCTURAL-PROPERTIES OF CU TE BI-LAYERS PREPARED BY RF-SPUTTERING/

Cu/Te bi-layers were deposited on glass, silicon (Si) single crystals, and on CdTe-coated glass substrates. The structural properties of the se samples were investigated using grazing-incidence X-ray diffraction (GIXD). As-deposited samples showed various structural properties and phase formation depending on the nature of the substrate. Samples dep osited on glass (amorphous substrate) did not reveal any crystallizati on on the surface layer, while those made on Si(lll) and polycrystalli ne CdTe films showed Cu2-xTe with a degree of crystallization dependin g on the substrate. Towards the volume, Cu2-xTe was observed in all th e samples with variable degrees of crystallization. Compound formation after annealing at 450 K was investigated. Particularly, Cu2-xTe <-> Cu7Te5 phase transformations were observed in samples deposited on pol ycrystalline CdTe films after annealing at 450 K. The structural diffe rences between the samples are correlated with the nature of the lat t ice in which both Cu and Te diffuse, which is more ordered in samples deposited on single crystal substrates and disordered in those made on amorphous substrates.