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Silicon carbide (SiC) is utilized in the automotive, semiconductor, and aerospace industries because of its desirable characteristics. Nevertheless, the traditional machining method induces surface microcracks, low geometrical precision, and severe tool wear due to the intrinsic high brittleness and hardness of SiC. Femtosecond laser processing as a high-precision machining method offers a new approach to SiC processing. However, during the process of femtosecond laser ablation, temperature redistribution and changes in geometrical morphology features are caused by alterations in carrier density. Therefore, the current study presented a multi-physics model that took carrier density alterations into account to more accurately predict the geometrical morphology for femtosecond laser ablating SiC. The transient nonlinear evolutions of the optical and physical characteristics of SiC irradiated by femtosecond laser were analyzed and the influence of laser parameters on the ablation morphology was studied. The femtosecond laser ablation experiments were performed, and the ablated surfaces were subsequently analyzed. The experimental results demonstrate that the proposed model can effectively predict the geometrical morphology. The predicted error of the ablation diameter is within the range from 0.15% to 7.44%. The predicted error of the ablation depth is within the range from 1.72% to 6.94%. This work can offer a new way to control the desired geometrical morphology of SiC in the automotive, semiconductor, and aerospace industries. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is a promising semiconductor material as well as a challenging material to machine, owing to its unique characteristics including high hardness, superior thermal conductivity, and chemical inertness. The ultrafast nature of femtosecond lasers enables precise and controlled material removal and modification, making them ideal for SiC processing. In this review, we aim to provide an overview of the process properties, progress, and applications by discussing the various methodologies involved in femtosecond laser processing of SiC. These methodologies encompass direct processing, composite processing, modification of the processing environment, beam shaping, etc. In addition, we have explored the myriad applications that arise from applying femtosecond laser processing to SiC. Furthermore, we highlight recent advancements, challenges, and future prospects in the field. This review provides as an important direction for exploring the progress of femtosecond laser micro/nano processing, in order to discuss the diversity of processes used for manufacturing SiC devices. [ABSTRACT FROM AUTHOR]

The femtosecond laser ablation of a wide bandgap semiconductor is characterized by a complicated energy transfer and rarely explored process. A coupled two-temperature-Fourier heat conduction model is developed to investigate the energy deposition and material removal mechanisms of femtosecond laser ablating silicon carbide (SiC). Absorption mechanisms, temperature distribution, and threshold fluence are investigated. Non-thermal melting and thermal melting processes are calculated. The results show that during the interaction between laser and SiC, the main absorption mechanism was governed by multiphoton absorption and Auger recombination. Simulation results of the new model show that the influence of latent heat on lattice temperature is insignificant and the heat accumulation on the surface is little. The obtained damage threshold represents reasonable prediction, based on comparison with experimental and literature data. The damage threshold and the non-thermal melting threshold for 800 nm increase with the pulse duration. The thermal melting occurs immediately after non-thermal melting at high fluence. The molten layer thickens logarithmically with the increase of the fluence. [ABSTRACT FROM AUTHOR]

Femtosecond laser processing technology offers a promising technique for the preparation of micro and nanostructures of single-crystal silicon carbide (SiC), thanks to its high precision and non-destructive processing. However, further research is needed to optimize processing parameters, as well as improve efficiency and quality of the process. This study conducts experiments to explore the effects of femtosecond laser ablation on single-crystal SiC. The influence and significance of parameters, such as fluence (F), repetition rate, scan speed (S), multipass scanning (c) and numerical aperture on the performance of grooves, including groove depth, groove width, heat-affected zone (HAZ) width, material removal rate (MRR) and side wall inclination angle, were studied. The results show that the influence of fluence and numerical aperture on groove depth, groove width, HAZ width, MRR and side wall inclination angle is very significant. The scan speed has a very significant effect on the groove depth, groove width, HAZ width and side wall inclination angle but has insignificant effect on the MRR. Repetition rate and multipass scanning have a very significant effect on groove depth, HAZ width, MRR and side wall inclination angle and a moderately significant effect on groove width. The experimental methods of increasing the aspect ratio and reducing the HAZ width were studied, and a significance analysis was carried out. Fluence, multipass scanning and z-layer feed have significant effects on groove depth, groove width, aspect ratio, HAZ width and MRR. The influence of polarization angle on groove depth, groove width, aspect ratio and MRR is insignificant. [ABSTRACT FROM AUTHOR]