Patent · US Expired

Method for distortion correction in a microlithographic projection exposure apparatus

US7372539B2 · kind B2 · utility

6Cited by

5References

18Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Andreas Kirchner · Wallenhorst, DE
Bernhard Kneer · Riedlingen, DE
Hans-Jurgen Mann · Oberkochen, DE

Key dates

Filing date	Mar 31, 2004
Grant date	May 13, 2008
Priority date	—
Expiry date	Mar 31, 2024

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70716
WIPO fieldOptics
WIPO sectorInstruments

Abstract

For the correction of anamorphism in the case of a projection lens of an EUV projection exposure apparatus for wafers it is proposed to tilt the reticle bearing the pattern to be projected and preferably also the wafer by a small angle about an axis that is perpendicular to the axis A of the lens and perpendicular to the scan direction and that in each instance passes through the middle of the light field generated on the reticle or on the wafer. For the correction of a substantially antisymmetric quadratic distortion the reticle and/or the substrate is instead rotated about an axis of rotation that is disposed at least approximately parallel to an optical axis of the projection lens.

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