Illumination system with curved 1d-patterned mask for use in EUV-exposure tool
US11300884B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2019 |
| Grant date | Apr 12, 2022 |
| Priority date | — |
| Expiry date | Nov 8, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70316
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A catoptric system having a reference axis and including a reflective pattern-source (carrying a substantially one-dimensional pattern) and a combination of two optical reflectors disposed sequentially to transfer EUV radiation incident onto the first optical component to the pattern-source the substantially one-dimensional pattern of which is disposed in a curved surface. In one case, such combination includes only two optical reflectors (each may contain multiple constituent components). The combination is disposed in a fixed spatial and optical relationship with respect to the pattern-source, and represents an illumination unit (IU) of a 1D EUV exposure tool that additionally includes a projection optical sub-system configured to form an optical image of the pattern-source on an image plane with the use of only two beams of radiation. These only two beams of radiation originate at the pattern-source from the EUV radiation transferred onto the pattern-source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.