Electrochemical etching of n-type 15R-SiC and 6H-SiC without UV illumination

We report the formation of porous n-type 15R- and 6H-SiC and analyze the porous layers using scanning electron microscopy, Raman scattering and X-ray diffraction (XRD). The crystal structures and the preparation conditions of porous SiC are shown to have an effect on the structural and electrical properties of the material obtained. Raman spectra of porous SiC layers have shown some specific features compared with those of bulk SiC. For the porous 15R-SiC, the semi-cylindrical structure of the porous network has been observed and the porosity is about 66%.