Nanosecond laser irradiation assisted chemical mechanical polishing (CMP) process for promoting material removal of single crystal 4H–SiC

Silicon carbide (SiC) is one of the most promising three-generation semiconductor materials owing to its remarkable properties and numerous potential applications. Nevertheless, the polishing efficiency of hard-to-process single-crystal SiC remains a significant challenge due to its high hardness and chemical inertness. A novel approach by employing nanosecond laser irradiation as a pre-process for the chemical mechanical polishing (CMP) process was presented. By irradiating the Si-face, the substrates were processed with CMP for a short time using normal 1 wt% diamond+ 99 wt% deionized water eco-friendly slurry. The performance of nanosecond laser irradiation assisted chemical mechanical polishing (NLIA-CMP), including material removal rate (MRR) and surface roughness (Ra), was evaluated. Besides, the possible effects were investigated. Atomic force microscopy (AFM) was used to observe the morphologies of SiC wafers after NLIS-CMP. The scanning electron microscopy (SEM) and the energy dispersive spectrometer (EDS) were used to characterize the surface morphologies and chemical composition of the SiC wafers treated with nanosecond laser. The results indicate that a highly efficient SiC-CMP with good surface quality can be realized by employing nanosecond laser irradiation as the pre-treatment and using an eco-friendly polishing slurry. The present study was a beneficial exploration of expanding the application of nanosecond laser to the CMP process.