Finite element modeling of nanoindentation and scratching of Si, SiC, Ge crystals with anisotropic plasticity

Abstract

Parameters of Hill's anisotropic elastoplasticity for diamond and Si, SiC, Ge semiconductors have been estimated from nonlinear stress-strain curves obtained by computational quantum chemistry. Using these parameters, finite element modeling of nanoindentation with Berkovich pyramid and frictionless scratching with spherical tip have been carried out. It has been shown, that the plastic anisotropy leads to the hardness anisotropy commonly observed by experimental indentation of (111), (011) and (001) crystallographic surfaces of the diamond-like crystals. The creep flow has been regarded in a quasi-static approach. Propagation of a median crack has been accounted by cohesive zone model.