Surface cleaning process for plasma-etched SiC wafer

In this paper, we explored a method to remove the contamination and impurities left on SiC surface after plasma-etched process. The stubborn contamination is resulting from fluorochemical caused by plasma-etched process, residue left after stripping Ni metal mask, Ni–O compounds formed by the metal mask with SiC Si surface oxide film and carbon-containing contamination introduced by the process environment. By adding a layer of SiO2 mask between SiC and the original metal mask together with ultrasonic cleaning and oxygen plasma cleaning process, the sample surface roughness was effectively reduced from 1.090 to 0.055 nm. Moreover, this method supplies a valuable reference for solving the problem of surface contamination caused by plasma etched.