Investigation on surface generation mechanism of single-crystal silicon in grinding: Surface crystal orientation effect

The ultra-precision grinding process of single-crystal silicon workpieces is crucial to obtaining wafers with high surface quality and service life. However, the quality of wafer processing is not only related to the grinding parameters but also the crystal orientations of the machined surface. In this work, the grinding process of single-crystal silicon workpieces under different crystal orientations is simulated by the molecular dynamics (MD) method, and the surface generation and subsurface damage mechanism are elucidated. The simulation results show the effect of the crystal orientation on the atomic displacement and crystal structure transition, which leads to differences in grinding force, grinding temperature distribution, and internal stress transmission. This work provides atomic-level insights to select a better crystal orientation of the wafer surface for processing. Lower subsurface damage layer (SDL) thickness, grinding temperature, and residual stress distribution appeared during the workpiece surface machining under {111} crystal orientation. Whereas lower processing force appeared under {100} crystal orientation during the workpiece surface machining. At the same time, the {100} crystal orientation has the lowest degree of phase transition by the analysis of the radial distribution function (RDF) as well as the coordination number (CN).