Accelerated ICP etching of 6H-SiC by femtosecond laser modification

A method for ultrafast etching of single crystal 6H-SiC by integrating a femtosecond laser modification and inductively coupled plasma (ICP) etching is proposed in this paper. The effect of single pulse energy and scanning rate of the femtosecond laser on ICP etching rate of 6H-SiC was investigated. The result shows that, compared with the untreated 6H-SiC, the ICP etching rate of the sample irradiated by a femtosecond laser with single pulse energy of 25 μJ and scanning rate of 20 μm/s increased by 117%, reaching 9365 Å/min on average during the accelerated etching process. Energy dispersive spectrum (EDS), Raman spectra and X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD), Auger electron spectroscopy (AES), and Atomic Force Microscope (AFM) were adopted to analyse the accelerated ICP etching mechanism. The analysis revealed that the femtosecond laser-induced SiO₂ on top of the 6H-SiC substrate is the primary cause of the accelerated ICP etching; the roughened surface formed during the irradiation also contributed to the improvement of the etching rate. The results of this study contribute to the technological development of SiC-based electronic components.