Publications Details
Plasma Chemistries for High Density Plasma Etching of SiC
A variety of different plasma chemistries, including SF6, Cl2, IC1 and IBr, have been examined for dry etching of 6H-SiC in high ion density plasma tools (Inductively Coupled Plasma and Electron Cyclotron Resonance). Rates up to 4,500~"min-1 were obtained for SF6 plasmas, while much lower rates (S800~.min-') were achieved with Cl2, ICl and IBr. The F2- based chemistries have poor selectivity for SiC over photoresist masks (typically 0.4-0.5), but Ni masks are more robust, and allow etch depths 210pm in the SiC. A micromachining process (sequential etch/deposition (<2,000Angstrom min-1) for SiC steps) designed for Si produces relatively low etch rates.