Patent ID: 7045464

Claim:
A method of etching a dielectric layer and a cap layer over a conductor level to open a via to a conductor, a pattern for the via being provided by a photoresist, the method comprising the steps of: etching the via through the dielectric layer; stripping the photoresist using a plasma chemistry including tetrafluoro methane (CF 4 ); and etching the cap layer to open the via to the conductor; wherein the dielectric layer etching step includes using approximately 80 mT of pressure, an RF energy of approximately 1200 W at 27 MHz and approximately 2700 W at 2 MHz, and a gas flow including tetrafluoro methane (CF 4 ) and carbon monoxide (CO) in a gas flow ratio of no less than approximately 0.104 and no greater than approximately 0.2.