INFLUENCE OF STRAIN ON SEMICONDUCTOR THIN-FILM EPITAXY

Under typical growth conditions, strain levels greater than or equal t o 10(-4) are shown to influence thin film surface morphology and strai n relaxation pathways. Misfit and threading dislocations in relaxed he terostructures produce long wavelength undulations on the surface and shallow depressions, respectively. Threading dislocation densities gre ater than similar to 10(5)-10(6) cm(-2) in relaxed heterostructures mu st be due to increased impediments to dislocation motion, which in tur n originate from the effect of the misfit dislocations on the surface morphology. Under typical growth conditions, the origin of strain-indu ced surface features can be identified by recognizing the length scale at which the features occur. (C) 1997 American Vacuum Society.