Method for residue-free block pattern transfer onto metal interconnects for air gap formation
US9390967B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 11, 2014 |
| Grant date | Jul 12, 2016 |
| Priority date | — |
| Expiry date | Feb 17, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32133
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A selective wet etching process is used, prior to air gap opening formation, to remove a sacrificial nitride layer from over a first region of an interconnect dielectric material containing a plurality of first conductive metal structures utilizing a titanium nitride hard mask portion located over a second region of the interconnect dielectric material as an etch mask. The titanium nitride hard mask portion located over the second region of the interconnect dielectric material is thereafter removed, again prior to air gap opening formation, utilizing another wet etch process. The wet etching processes are used instead of reactive ion etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.