Patent · US Expired

Optimized polarization illumination

US7292315B2 · kind B2 · utility

15Cited by

3References

16Claims

0Family size

Assignee

ASML Masktools B.V. · NL

Inventors

Robert John Socha · Campbell, US
Donis Flagello · Rue de l'Église, US
Steve Hansen · Phoenix, US

Key dates

Filing date	Aug 20, 2004
Grant date	Nov 6, 2007
Priority date	—
Expiry date	Mar 17, 2025

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70616
WIPO fieldOptics
WIPO sectorInstruments

Abstract

Disclosed concepts include a method of optimizing polarization of an illumination of a pattern to be formed in a surface of a substrate. Polarized illumination is optimized by determining an illumination intensity for at least one point on an illuminator for at least two polarization states, determining image log slope for the at least one point on the illuminator for the at least two polarization states, determining a maximum image log slope (ILS) where the ILS is near zero for the at least one point on the illuminator, and selecting an optimal polarization state corresponding to the at least two polarization states that minimizes an ILS for the at least one point on the illuminator. This may be repeated for a plurality of points on the illuminator.

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