| 摘要 |
The present invention provides a low-k dielectric etching process with high etching selectivities with respect to adjacent layers of other materials, such as an overlying photoresist mask and an underlying barrier/liner layer. The process comprises the step of exposing a portion of the low-k dielectric layer to a plasma of a process gas that includes a 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 fluorocarbon gas is greater than about 20:1. The process can be used to over etch the low-k dielectric layer to provide improved selectivity to the photoresist mask and the barrier/liner layer, reduced striations and reduced CD loss as compared with conventional low-k dielectric etching processes.
|
