Polycrystalline silicon were grown at high temperature in a gas-source molecular beam epitaxy (MBE) and then exposed to cavitation impacts from the backside at different scanning times to introduce compressive stress. The micro-Raman spectroscopy showed that regions of greater structural change due to cavitation impacts experience higher full width at half maximum (FWHM) and that stress was a function of number of scans. AFM was used to analyze the surface morphology of the specimen in the as-grown condition and after exposed to cavitation impacts. The structural features were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). HRTEM observations showed that nanoparticles size of grains at the growth/death zone of interface. The dislocations types, twinnings and defects caused by cavitation impacts are discussed.