STRUCTURAL DISORDER IN SIGE FILMS GROWN EPITAXIALLY ON SI BY ION-BEAMSPUTTER-DEPOSITION

SiGe/Si heterostructures grown by ion beam sputter deposition were cha racterized by high-resolution X-ray diffraction and transmission elect ron microscopy. Agglomerates of point defects, formed under ion bombar dment during growth, were observed in electron microscopy images. Thes e specific defects resulted in structural disorder which could be desc ribed in terms of local fluctuations of interplanar distances. The ave raged magnitudes of the fluctuations were derived from X-ray diffracti on spectra using a novel simulation procedure based on the direct summ ation of scattered waves in imperfect heterostructures. This approach allowed us to characterize quantitatively the degree of the structural disorder, and to follow defect transformations as a function of growt h and annealing temperatures.