Low damage, highly anisotropic dry etching of SiC

A parametric study of the etching characteristics of 6H p/sup +/ and n/sup +/ SiC and thin film SiC/sub 0.5/N/sub 0.5/ in Inductively Coupled Plasma NF/sub 3//O/sub 2/ and NF/sub 3//Ar discharges has been performed. The etch rates in both chemistries increase monotonically with NF/sub 3/ percentage and rf chuck power. The etch rates go through a maximum with increasing ICP source power, which is explained by a trade-off between the increasing ion flux and the decreasing ion energy. The anisotropy of the etched features is also a function of ion flux, ion energy and atomic fluorine neutral concentration. Indium-tin-oxide (ITO) masks display relatively good etch selectivity over SiC (maximum of /spl sim/70:1), while photoresist etches more rapidly than SiC. The surface roughness of SiC is essentially independent of plasma composition for NF/sub 3//O/sub 2/ discharges, while extensive surface degradation occurs for SiCN under high NF/sub 3/:O/sub 2/ conditions.