| abstract |
Provided is a novel etching gas composition that comprises a sulfur-containing compound and that can selectively etch SiO<sub>2</sub> over low dielectric constant materials (low-k materials; SiON, SiCN, SiOCN, SiOC).A dry etching gas composition comprises a saturated and cyclic sulfur-containing fluorocarbon compound that is represented by general formula (1) of C<sub>x</sub>F<sub>y</sub>S<sub>z</sub> where x, y, and z are 2 ≤ x ≤ 5, y ≤2x, and 1 ≤ z ≤ 2. |