Patent · US Active

Illumination optic for EUV projection lithography

US10379444B2 · kind B2 · utility

0Cited by

5References

23Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Matthias Mueller · Harsefeld, DE
Thomas Fischer · Umkirch, DE
Stefan Seitz · Windach, DE

Key dates

Filing date	Nov 16, 2017
Grant date	Aug 13, 2019
Priority date	—
Expiry date	Nov 16, 2037

Classification

Technology area (CPC G)Physics
CPC primaryG21K2201/065
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An illumination optical unit for EUV projection lithography illuminates an object field with illumination light. The illumination optical unit has a first facet mirror including a plurality of first facets on a first mirror carrier. Disposed downstream of the first facet mirror is a second facet mirror including a plurality of second facets arranged on a second mirror carrier around a facet arrangement center. Partial beams of the illumination light are guided superposed on one another into the object field, respectively via illumination channels which have one of the first facets and one of the second facets. Second maximum angle facets are arranged at the edge of the second mirror carrier. The second maximum angle facets predetermine maximum illumination angles of the illumination light which deviate maximally from a chief ray incidence on the object field.

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