• Femtosecond laser ablation of SiC primarily involves melting and vaporization, with vaporization as the dominant material removal mechanism.
• Micro-groove depth and width increase with higher pulse energy, pulse overlap rate, and number of passes.
• Bottom roughness correlates positively with pulse energy, negatively with pulse overlap rate, and is minimally affected by number of passes.
• The study provides theoretical insights for optimizing high-quality and high-efficiency femtosecond laser processing of SiC micro-grooves.