Reflective mask blank, reflective mask, method of manufacturing reflective mask blank, and method of manufacturing reflective mask
US12105412B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2024 |
| Grant date | Oct 1, 2024 |
| Priority date | — |
| Expiry date | Feb 16, 2044 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C14/34
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A reflective mask blank for EUV lithography includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light. The substrate, the multilayer reflective film, the protection film, and the absorption film are arranged in this order from bottom to top. The protection film includes an upper layer made of a rhodium-based material containing Rh as a main component that contains only Rh, or contains Rh and at least one element selected from a group consisting of N, O, C, B, Ru, Nb, Mo, Ta, Ir, Pd, Zr, and Ti; and a lower layer satisfying a condition k<−0.15n+0.16 in an EUV region where n represents a refractive index and k represents an extinction coefficient.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.