ATOMIC-FORCE MICROSCOPY STUDIES OF SIGE FILMS AND SI SIGE HETEROSTRUCTURES/

Atomic force microscopy (AFM) is used to study the topography of strai ned SiGe films and multilayer Si/SiGe heterostructures. Strain relaxat ion processes are found to determine the formation of surface morpholo gy, with distinct morphological features arising from both misfit disl ocation formation and three-dimensional growth of coherent islands and pits on the surface. Studies of these features for various values of strain (Ge content) and growth temperature reveal the underlying physi cal processes determining the strain relaxation. Fourier analysis of A FM images is performed to obtain quantitative roughness information an d to separate roughness components of different physical origin.