Patent · US Active

Imaging optical unit for a metrology system for examining a lithography mask

US10606048B2 · kind B2 · utility

2Cited by

3References

21Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Johannes Ruoff · Aalen, DE
Ralf Müller · Geringswalde, DE
Susanne Beder · Aalen, DE
Ulrich Matejka · Jena, DE
Hans-Jurgen Mann · Oberkochen, DE
Jens Timo Neumann · Shanghai, CN

Key dates

Filing date	Jan 20, 2017
Grant date	Mar 31, 2020
Priority date	—
Expiry date	Aug 16, 2037

Classification

Technology area (CPC G)Physics
CPC primaryG21K7/00
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An imaging optical unit serves within a metrology system for examining a lithography mask. The lithography mask can be arranged in an object field of the imaging optical unit. The object field is defined by two mutually perpendicular object field coordinates. The imaging optical unit has an aperture stop of which the aspect ratio in the direction of the two object field coordinates differs from 1. This results in an imaging optical unit which can be used for the examination of lithography masks that are designed for projection exposure with an anamorphic projection optical unit.

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