Reflection mode photomask
US11270884B2 · kind B2 · utility
2Cited by
2References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 27, 2020 |
| Grant date | Mar 8, 2022 |
| Priority date | — |
| Expiry date | Feb 6, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0276
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A reflection mode photomask includes a substrate. The reflection mode photomask further includes a reflective multilayer over the substrate. The reflection mode photomask further includes a plurality of absorber stacks over the reflective multilayer, wherein each absorber stack of the plurality of absorber stacks has an etch stop layer, an absorber layer and an ARC layer, wherein a ratio of a thickness of the ARC layer to that of the etch stop layer is in a range from about 1:1 to about 1:2.5, and a sidewall roughness of each absorber stack of the plurality of absorber stacks is smaller than 3 nanometers (nm).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.