Patent ID: 7229930
Filing Date: 2007-06-12
Classification: H01L

Abstract:
1. A method of selectively etching a low-k dielectric layer, the method comprising: providing a flow of a process gas into a process zone in which the low-k dielectric layer masked by a photoresist material is located, the process gas including a first fluorocarbon gas having a relatively low fluorine to carbon ratio, a nitrogen-containing gas, and an inert gas, wherein a volumetric flow ratio of the nitrogen-containing gas to the first fluorocarbon gas is greater than 30:1; and maintaining a plasma of the process gas to etch the low-k dielectric layer with a low-k dielectric to photoresist etching selectivity ratio greater than about 4.8:1, and a low-k dielectric etch rate greater than about 1400 Å/min.