Novel Electrochemical Patterning Method of Silicon Carbide

Silicon Carbide (SiC) is the most promising material for the fabrication of a new category of sensors and devices, to be used in very hostile environments (height temperature, corrosive ambient, presence of radiation ...). The fabrication of Silicon Carbide sensors requires new processes able to realize microstructures on bulk material or on the silicon carbide surface. A very promising method to create microstructures in SiC is the electrochemical etch in aqueous solution of hydrofluoric acid. In this paper the bulk micromachining of SiC substrate and the structural and electrical characterization of porous silicon carbide formation are reported. These results were used to create a novel method for the bidimensional pattering of SiC substrate. In particular a novel Si-based hard mask to transfer the design onto the SiC substrate was used. The hard mask is formed by a sandwich structures made by subsequent deposition of VAPOX, POLY Si, SiO2.