Cross-sectional observation on the indentation of [001] silicon

Abstract

A transmission electron microscope (TEM) micrograph of cross-sectionally viewed Vickers indentation made on the surface of (001) silicon at ambient temperature was obtained. The picture clearly reveals a triangle area, pointing downward and having nondiffraction-contrast, left after unloading, which further confirms the amorphized range induced by indentation in silicon. Analysis of the picture directly manifests a significant recovery of indentation depth. Surface shape and range of the amorphous silicon region do not coincide with that of the indenter and the corresponding distribution pattern of hydrostatic stress beneath indentation predicted by elastoplastic theory, respectively. It seems that the amorphization could not be attributed to the result of hydrostatic stress alone.