Surface treatment method for dielectric anti-reflective coating (DARC) to shrink photoresist critical dimension (CD)
US9880473B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2016 |
| Grant date | Jan 30, 2018 |
| Priority date | — |
| Expiry date | Jun 22, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/167
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A KrF (248 nm) photoresist patterning process flow is disclosed wherein photoresist patterns having a sub-100 nm CD are formed on a dielectric antireflective coating (DARC) thereby lowering cost of ownership by replacing a more expensive ArF (193 nm) photoresist patterning process. A key feature is treatment of a DARC such as SiON with a photoresist developer solution that is 0.263 N tetramethylammonium hydroxide (TMAH) prior to treatment with hexamethyldisilazane (HMDS) in order to significantly improve adhesion of features with CD down to about 60 nm. After the HMDS treatment, a photoresist layer is coated on the DARC, patternwise exposed, and treated with the photoresist developer solution to form a pattern therein. Features that were previously resolved by KrF patterning processes but subsequently collapsed because of poor adhesion, now remain upright and intact during a subsequent etch process used to transfer the sub-100 nm features into a substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.