Patent ID: 7311852
Filing Date: 2007-12-25
Classification: H01L

Abstract:
1. A process for etching a low-k dielectric layer with selectivity to an overlying mask layer, comprising the steps of: supporting a semiconductor substrate in a chamber of a plasma etch reactor, the semiconductor substrate having a low-k dielectric layer of a carbon-doped glass low-k material and an overlying mask layer; supplying an oxygen-free single-fluorocarbon etching gas to the chamber and energizing the etching gas into a plasma state, the etching gas consisting essentially of N etching exposed portions of the low-k dielectric layer with the plasma so as to etch openings in the low-k dielectric layer with the plasma while providing a etch rate selectivity of the etching rate of the low-k dielectric layer to the etching rate of the mask layer of at least about 5, wherein the plasma etch reactor comprises a dual frequency parallel plate plasma reactor having a showerhead electrode and a bottom electrode on which the substrate is supported.