Patent ID: 7112534

Claim:
A method of forming a microelectronic structure comprising: forming and patterning a deep uv resist layer on a sacrificial light absorbing layer disposed on a dielectric layer; etching the sacrificial light absorbing layer in a plasma comprising a C 4 F 6 gas flow from about 14 to about 20 sccm, an argon flow from about 300 to about 500 sccm, a nitrogen flow from about 200 to 400 sccm and a pressure from about 40 to about 60 millitorr; and etching the dielectric layer in a plasma comprising a C 4 F 6 gas flow from about 10 to about 14 sccm, an argon flow from about 280 to about 350 sccm, a nitrogen flow from about 25 to 40 sccm and a pressure from about 80 to about 120 millitorr, wherein the sacrificial light absorbing layer and the dielectric layer etch at an etch rate from about 80 to about 120 times faster than the etch rate of the deep uv resist layer.