Method and apparatus for EUV mask inspection
US11635700B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Mar 23, 2021 |
| Grant date | Apr 25, 2023 |
| Priority date | — |
| Expiry date | Mar 23, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05G2/001
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for producing a protective buffer flow in an EUV light source and an EUV mask inspection apparatus are provided. The method includes directing light along a light path from the EUV light source toward a collector. A first buffer gas from a buffer gas injector is injected through a plurality of through holes in the collector. The first buffer gas is directed away from a surface of the collector. A second buffer gas is injected from a ring manifold arranged peripherally to the collector and arranged a first distance toward the light path in relation to the collector. The second buffer gas is directed away from the surface of the collector. The first distance corresponds to a distance from the collector where the first buffer gas merges into a single flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.