Characterization of Micro-grooves Processed Using a Green Femtosecond Laser in Silicon Carbide
Authors: Lijuan Zheng, Xiangqian Xu, Wenwen Tao, Yong Sun, Yongfeng Zhao, Chuanhong Hu, Xiongbing Tao, Xin Wei, Chengyong Wang
Silicon carbide (SiC) is widely used in fields such as new energy, military radar, and aerospace due to its outstanding physical and chemical properties. The surface micro-grooves of SiC can enhance the performance of micro-electro-mechanical systems, micro-sensors, and field-effect transistors. However, SiC, being a brittle and hard material, poses challenges for traditional machining methods like micro-groove machining and chemical etching, including sub-surface damage, short tool life, and low processing efficiency. This paper investigates the processing characteristics of femtosecond laser machining of SiC micro-grooves and compares them with those of single-crystal Si. The results indicate that femtosecond laser ablation of SiC primarily leads to melting and vaporization, forming modification, melted, and ablation areas in the affected area. Femtosecond laser processing of SiC micro-grooves involves three processes: heat absorption and melting, vaporization, and chipping, with vaporization as the primary material removal mechanism. The depth and width of SiC micro-grooves are positively correlated with pulse energy (Ep), pulse overlap rate (PO), and number of passes (Npass). The bottom roughness of the micro-grooves is positively correlated with Ep, negatively correlated with PO, and less affected by changes in the Npass. These findings further elucidate the material removal and micro-groove formation mechanisms of SiC under femtosecond laser irradiation, providing theoretical insights for high-quality and high-efficiency processing of SiC micro-grooves.
