Patent · US Active

Optical system, in particular for a microlithographic projection exposure apparatus

US10520827B2 · kind B2 · utility

0Cited by

10References

21Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Hartmut Enkisch · Aalen, DE
Thomas Schicketanz · Aalen, DE
Matus Kalisky · Aalen, DE
Oliver Dier · Lauchheim, DE

Key dates

Filing date	Jan 7, 2019
Grant date	Dec 31, 2019
Priority date	—
Expiry date	Jan 7, 2039

Classification

Technology area (CPC G)Physics
CPC primaryG21K1/067
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An optical system, in particular for a microlithographic projection exposure apparatus, with at least one mirror (200) which has an optically effective surface and, for electromagnetic radiation of a predefined operating wavelength impinging on the optically effective surface at an angle of incidence of at least 65° relative to the respective surface normal, has a reflectivity of at least 0.5. The mirror has a reflection layer (210) and a compensation layer (220) which is arranged above this reflection layer (210) in the direction of the optically effective surface. The compensation layer (220), for an intensity distribution generated in a pupil plane or a field plane of the optical system during operation thereof, reduces the difference between the maximum and the minimum intensity value by at least 20% compared to an analogous structure without the compensation layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.