FINE PATTERN ETCHING TECHNIQUE OF SILICON SUBSTRATE.

The authors describe a newly developed RIE technique using some additional gases to SF6. They have succeeded in getting high-selectivity to photo resist and a clean etched surface with no residue, which were difficult to achieve in usual directional silicon etching. The suppression mechanism of the undercut was studied, and then both high aspect ratio patterns and controlled tapered patterns of silicon were obtained by the choice of the gas mixing ratio.