Anodic etching of SiC in alkaline solutions

Abstract

The photoelectrochemistry of silicon carbide in alkaline solution was investigated with a view to wet-chemical etching applications. Anodic dissolution and passivation of the p-type semiconductor was observed in the dark; illumination with supra-bandgap light was required for oxidation of the n-type electrode. At low KOH concentrations and low light intensities, diffusion-controlled etching is observed for n-type SiC. We show that open-circuit photoetching can be used for defect revealing. Furthermore, based on the electrochemical properties of silicon carbide and silicon, we expect various material-selective etching processes to be possible.