A method of etching porous dielectric

摘要

The present invention relates to methods of etching a porous dielectric. The method includes etching the film in a plasma etch chamber with CF4, H2 and a noble gas, wherein the CF4 to H2 gas flow ratio is between 1.33:1 and 2.7:1 and the noble gas is greater than about 42% of the total gas flow to the plasma chamber.