Molecular dynamics simulation on subsurface damage layer during nano grinding process of silicon wafer

The subsurface damage has a siginificant effect on the strength of the wafer. To investigate the effect of the grinding speed and depth of cut on the surface and subsurface damage, a series of large scale MD simulation of nano grinding of silicon is performed. The results show that the monocrystalline silicon lattice undergoes extrusion and shear deformation, lattice reconstruction and amorphous phase transformation are also observed during the grinding process. It also turned that the grinding speed has an optimal value approximately 160m/s in the range of 50–400 m/s. By considering the variation of subsurface damage thickness for various depths of grinding at the grinding speed of 160m/s. The results show that the subsurface damage are gradually increasing from 9.5 Å to 20.5 Å with the augment of the depth of cut from 5 Å to 30 Å. Based on the above conclusions, it can be predicted that smaller depth of cut could reduce subsurface damage.