Study of deformation mechanism of structural anisotropy in 4H–SiC film by nanoindentation

4H–SiC film is strongly anisotropic in terms of deformation behavior. This study systematically investigated the deformation mechanism of structural anisotropy in 4H–SiC film on three indentation planes (i.e. base plane, a-plane and m-plane) by nanoindentation. The results of molecular dynamics (MD) study show that the hardness and Young’s modulus of 4H–SiC film are different on three indentation planes. The morphology of the defective microstructures and the nucleation and extension of dislocations are strongly dependent on the indentation planes. The deformation behavior of 4H–SiC film is related to the crystal direction, atomic displacement, atomic strain and stress distribution. Further analysis reveals that the formation of prismatic dislocation half-loops on the basal plane (0001) can be attributed to the interaction of one full dislocation loop on the basal plane (0001) and two full dislocation loops on the prismatic plane {11‾00}. Whereas the prismatic dislocation loops on the a-plane (112‾0) and m-plane (11‾00) are formed by the “lasso"-like mechanism.