Research on the impact of grinding speed on surface/subsurface damage in monocrystalline silicon by workpiece rotational grinding

To investigate the effect of grinding speed on the surface/subsurface damage of monocrystalline silicon grinding, experiments of grinding monocrystalline silicon wafers with different grinding speeds under the condition of equal abrasive cutting depth were designed based on the workpiece rotation method. The surface morphology, roughness, surface cracks, deformations, and residual stresses after machining were analyzed through comparative experiments, and the reasons for the effect of different machining speeds on the number of cracks and depth of subsurface damage were analyzed in combination with molecular dynamics simulation models. The results indicated that with the increase in grinding speed, the surface quality gradually becomes better. Furthermore, when the grinding speed is 2399 rpm, the surface roughness Ra value formed by Nos. 600 and 5000 grinding wheels is reduced by 22.5% and 31.2%, respectively, compared with 239 rpm. Besides, when grinding with the No. 600 grinding wheel, the higher the grinding speed, the fewer the number of subsurface cracks and the smaller the crack depth. Besides, when the grinding speed is 2399 rpm, the number of cracks is reduced by about 50%, and the depth of cracks is reduced by about 25% compared with 239 rpm. Moreover, when grinding with the No. 5000 grinding wheel, the deformation and residual stress of the silicon wafer gradually decrease with the increase in grinding speed. The deformation formed at a grinding speed of 2399 rpm is about 44% lower than that at 239 rpm. With the increase in grinding speed, the number of cracks, deformation, and residual stress of silicon wafer are reduced. Moreover, the increase in grinding speed will help reduce the damage degree of the crystal structure and the thickness of the damage layer of the silicon wafer, thus improving the quality of the grinding surface.