Projection optical system, exposure apparatus, and device manufacturing method
US7053986B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2005 |
| Grant date | May 30, 2006 |
| Priority date | — |
| Expiry date | Nov 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70275
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection optical system projects an image of a first object onto a second object. A first imaging optical system forms a first intermediate image of the first object, and is a refractive optical system. A second imaging optical system forms a second intermediate image of the first object, and includes two mirrors, one of the two being concave. A third imaging optical system forms an image of the first object onto the second object, and includes a lens. The first, second and third imaging optical systems are arranged along an optical path from the first object in this order. The system satisfies the expression 0.80<|β1·β2<2.0 where β1 and β2 are paraxial magnifications of the first and second imaging optical systems, respectively. The first imaging optical system and the concave mirror have a common straight optical axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.