Selective etching of low-k dielectrics
US6897154B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Jun 14, 2002 |
| Grant date | May 24, 2005 |
| Priority date | — |
| Expiry date | Aug 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31144
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
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, a nitrogen-containing gas, and an inert gas, wherein the volumetric flow ratio of inert:fluorocarbon gas is in the range of 20:1 to 100:1, and the volumetric flow ratio of fluorocarbon:nitrogen-containing gas is selected to provide a low-k dielectric to photoresist etching selectivity ratio greater than about 5:1 and a low-k dielectric etch rate higher than about 4000 Å/min.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.