Plasma etching of SiC surface using NF3

NF 3 was applied in the reactive ion etching of SiC. The effects of rf power and NF3 pressure on the etching rate and the surface morphology were investigated by means of scanning electron microscopy and atomic force microscopy. A procedure for getting the smooth and residue-free etched surface of SiC with a high etching rate of 87 nm/min was obtained under the conditions such as rf power of 100 W and NF3 pressure ranging from 0.5 to 1 Pa. A rough surface with spikes was obtained under the NF3 pressures higher than 3 Pa. It was found that the repetitive alternating treatment for the spike-formed and rough surface with the down flow etching using NF3 and Ar plasma sputtering enables us to obtain the smooth surface within the scale of ∼300 nm.