Highly efficient planarization of sliced 4H–SiC (0001) wafer by slurryless electrochemical mechanical polishing

Abstract

Slurryless electrochemical mechanical polishing (ECMP) was proposed and directly applied to sliced 4H–SiC (0001) surfaces. After ECMP for 2 h at a current density of 10 mA/cm2 in sodium chloride aqueous solution using a #8000 ceria vitrified grinding stone, a scratch-free mirror surface was obtained, and the Sq roughness of the SiC surface decreased from 286 to 1.352 nm. The material removal rate was about 23 μm/h, and the saw marks and surface damage on the sliced surface were completely removed. Raman spectroscopy and X-ray photoelectron spectroscopy showed no subsurface damage or residual oxide on the ECMP-processed surface, and the quality of the surface was much higher than that obtained by conventional lapping. The results of this study suggest that the manufacturing process for SiC can be simplified by applying slurryless ECMP with a high material removal rate and low cost.