Patent · US Active

Optical system of a microlithographic projection exposure apparatus and method of reducing image placement errors

US9785052B2 · kind B2 · utility

0Cited by

2References

20Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Johannes Ruoff · Aalen, DE
Jens Timo Neumann · Shanghai, CN
Joerg Zimmermann · Vancouver, CA
Dirk Hellweg · Langenau, DE
Dirk Juergens · Munich, DE

Key dates

Filing date	Mar 11, 2013
Grant date	Oct 10, 2017
Priority date	—
Expiry date	Mar 23, 2035

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70633
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A method of reducing image placement errors in a microlithographic projection exposure apparatus includes providing a mask, a light sensitive layer and a microlithographic projection exposure apparatus which images features of the mask onto the light sensitive surface using projection light. Subsequently, image placement errors associated with an image of the features formed on the light sensitive surface are determined either by simulation or metrologically. Then an input state of polarization of the projection light is changed to an elliptical output state of polarization which is selected such that the image placement errors are reduced.

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