Chemistry for etching organic low-k materials
US6040248A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1998 |
| Grant date | Mar 21, 2000 |
| Priority date | — |
| Expiry date | Jun 24, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76802
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for plasma etching of contact and via openings in low-k organic polymer dielectric layers is described which overcomes problems of sidewall bowing and hardmask pattern deterioration by etching the organic layer in a high density plasma etcher with a chlorine/inert gas plasma. By adding chlorine to the oxygen/inert gas plasma, the development of an angular aspect or faceting of the hardmask pattern edges by ion bombardment is abated. Essentially vertical sidewalls are obtained in the openings etched in the organic polymer layer while hardmask pattern integrity is maintained. The addition of a passivating agent such as nitrogen, BCl.sub.3, or CHF.sub.3 to the etchant gas mixture further improves the sidewall profile by reducing bowing through protective polymer formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.