Investigation of damage generation process by stress waves during femtosecond laser drilling of SiC

Abstract Femtosecond laser processing has garnered significant attention as a method for micromachining silicon carbide (SiC), which is expected to be used in next-generation power semiconductors. However, a significant amount of damage is generated around the processing area during the femtosecond laser processing of SiC. In this study, high-speed phenomena during the femtosecond laser drilling of SiC are observed with high temporal and spatial resolutions by combining pump-probe imaging and a high-speed camera. In addition, a stress wave propagation simulation based on experimental results is conducted. Based on the experimental and simulation results, the mechanism of damage generation by the stress wave generated during material removal is elucidated. The damage generation mechanism elucidated in this study will facilitate the development of damage suppression methods and the expansion of industrial applications of SiC.