Abstract
As the most popular semiconductor material, silicon carbide has received extensive attention from the industry. In this study, a UV laser with a center wavelength of 343 nm, a pulse width of 500 fs, a maximum average power of 12 W, and an adjustable repetition rate of 400 similar to 500 kHz was used to conduct cutting process experiments on 4H-SiC. A 3D color scanning electron microscope (SEM) and a metallographic microscope are used to observe the cutting section and surface. The effects of laser repetition rate, laser average power, scanning speed and other process parameters on the cutting quality were studied. The ablation threshold of the silicon carbide was obtained to be 44.62 mJ/cm2. The best cutting result we made is at the condition with the laser average power 2W, the scanning speed 150mm/s, the repetition rate 500 kHz, and the scanning number 2 times. Using a metallurgical microscope, it was observed that the cutting surface was neat, without chipping or cracking, and the thermal effect was negligible. The 3D color SEM image are shown that the taper of the slit was 5.75 degrees and the roughness of the cut section was less than 2.69 mu m.