Role of hydrogen in dry etching of silicon carbide using inductively and capacitively coupled plasma

We investigated the etching mechanism of SiC using inductively and capacitively coupled plasma with CHF3 and SF6 gases. We discussed the effects of O2 and H2 gases on etching properties. By optimizing the conditions of Ha flow rate, we could confirm the improvement in etching rates. Surface roughness was also improved by the optimum addition of H2 gas. Analysis by XPS revealed that a fluorocarbon film was formed on the surface after etching with SF6 gas. Surface fluoride atomic concentration was reduced from 28 to 8 at.% by the addition of H2 gas. A H2 annealing suppressed the fluoride concentration of surface to less than 3 at.%. This processing technique is very effective for the fabrication of SiC devices. © 2005 The Japan Society of Applied Physics.