Patent ID: 7504338

Claim:
A method of pattern etching a layer of a silicon-containing dielectric material to form a hard mask, wherein a patterned photoresist layer used during etching of said hard mask is one which is sensitive to radiation exhibiting a wavelength within the range of about 100 nm to about 200 nm, whereby feature sizes of about 0.15 μm or smaller are created in said patterned photoresist and in said hard mask, wherein said pattern etching of said silicon-containing dielectric layer is accomplished using a plasma generated from a source gas, wherein chemically reactive etchant gases within said source gas consist essentially of CF 4 and CHF 3 , and wherein a volumetric ratio of CF 4 to CHF 3 is within a range of about 2:3 to about 3:1, whereby sidewalls of a pattern etched in said silicon-containing dielectric layer exhibit a surface roughness of less than about 5 nm.