Molecular dynamics simulations of nano-cutting of 4H-silicon carbide (SiC) by two diamond tools

The third generation semiconductors, such as Silicon Carbide (SiC), are widely used in aerospace, automobile and other industries. It has a lot of characteristics such as wide band gap, high thermal conductivity and high bonding energy etc. Since its hardness is only less than that of diamond, it is difficult to be cut during semiconductor process. SiC semiconductor devices are still mainly in the research and development stage, but the process is basically similar to Si semiconductor production process. The cutting process is the first stage during semiconductor process, during which crystal ingot is cut into wafer. This process produces a large number of surface defects. If the defects are not removed, the defects will be copied to the epitaxial layer. Therefore, it is necessary to remove surface damage and defects before the epitaxial process to improve the surface quality. The result shows the optimal tool parameters are small negative rake angle (-30 °) and large clearance angle (15 °). The cutting force in second cutting process is less than the first cutting process and it enters the stable stage more quickly. Considering that the second cutting process contains a part of the amorphous structure, the required cutting force will become smaller which means the material easier to remove.