Scratches on near (111) silicon slices

Abstract

Scratches made by a diamond stylus on silicon substrates with near (111) orientation have been investigated by optical microscopy and X-ray topography. It is found that the appearance of the scratch and the wide residual strain field detected by diffraction contrast are both anisotropic with respect to direction, but in opposite senses; maximum chipping and wear is associated with minimum width of strain field for scratches in or near (112), (211) and (121), and vice versa for (112), (211) and (121). It is concluded from a study of the topographic contrast in different reflections that the long-range field of residual elastic strain is in plane strain compression, and is associated with a system of cracks observed by optical microscopy. The implications of the observed anisotropy of chipping are discussed.