Principal Factors Affecting the Sub-Micrometer Grooving Mechanism of SiC Thin Layers by a 355 nm UV Laser

The machining of micro holes and grooves on single crystal SiC thin layers by a UV laser (355 nm wave length and 15 ps pulse width) is reported. It was verified that an optimum threshold, where both laser sublimation and photonic ablation can take place at the same time in order to obtain a micro sharp groove as 2 μm pitch and 0.4 μm depth, must be selected. Theoretically, laser photonic ablation may take place at a certain amount of laser fluence, and then SiC is sublimed once the influence exceeds another limit, and therefore, there is an optimum threshold between these two limits of laser fluence.