Illumination optic for projection lithography
US10928733B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 21, 2020 |
| Grant date | Feb 23, 2021 |
| Priority date | — |
| Expiry date | Jul 21, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70233
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illumination optical unit for projection lithography illuminates an object field with illumination light along an illumination beam path. The arrangement of field facets of a field facet mirror and also of pupil facets of a pupil facet mirror is such that an illumination channel is guided over each of them. The field facet mirror images a light source image along in each case one illumination channel onto one of the pupil facets. The pupil facet mirror superimposedly images of the field facets into the object field. The illumination optical unit is designed for the settable specification of a spatial resolution of an illumination light illumination of an entrance pupil of a projection optical unit arranged downstream of the object field in the illumination light beam path. The result of this is an illumination optical unit with which illumination light can be used efficiently for high-contrast imaging of the structures to be projected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.