Experimental study on femtosecond laser ablation of 4H-SiC substrate

Data Access Statement: Research data supporting this publication are available from the NN repository at located at www.NNN.org/download/. Silicon carbide (SiC) is an ideal substrate for manufacturing high-power electronic devices and microwave devices, and has broad application prospects. The surface treatment of SiC wafers plays a critical role and faces challenges in the semiconductor industry. Among the multiple treatment methods, the laser-based method has gradually attracted the attention of scholars. Therefore, this research uses a femtosecond laser to ablate 4H-SiC sliced wafers and analyzes the influence of key parameters, such as laser pulse energy, defocus amount, repetition frequency, and scanning intervals, on the laser ablation depth, width, and surface morphology. Scanning electron microscopy (SEM) and laser coherence-focused microscopy were used to characterize the laser ablation surface. The results show that under a defocus amount of +6 mm, a laser pulse energy of 87.5 μJ, scanning speed of 500 mm/s, and pulse frequency of 300 kHz. The results show that the optimized surface roughness (Sa) was 0.267μm, and brittle fracture areas such as microcracks and pits on the original surface were removed. Effective removal facilitates further material surface processing, which provides valuable insights for similar researchers and benefits for the semiconductor industry. Ethical Compliance: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.