Protection layer on low thermal expansion material (LTEM) substrate of extreme ultraviolet (EUV) mask
US12001132B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2019 |
| Grant date | Jun 4, 2024 |
| Priority date | — |
| Expiry date | Sep 12, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0274
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Fabricating a photomask includes forming a protection layer over a substrate. A plurality of multilayers of reflecting films are formed over the protection layer. A capping layer is formed over the plurality of multilayers. An absorption layer is formed over capping layer. A first photoresist layer is formed over portions of absorption layer. Portions of the first photoresist layer and absorption layer are patterned, forming first openings in absorption layer. The first openings expose portions of the capping layer. Remaining portions of first photoresist layer are removed and a second photoresist layer is formed over portions of absorption layer. The second photoresist layer covers at least the first openings. Portions of the absorption layer and capping layer and plurality of multilayer of reflecting films not covered by the second photoresist layer are patterned, forming second openings. The second openings expose portions of protection layer and second photoresist layer is removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.