Patent · US Expired

Method of improving photomask geometry

US6846595B2 · kind B2 · utility

7Cited by

17References

31Claims

0Family size

Assignee

ASML NETHERLANDS B.V. · NL

Inventor

Bruce W. Smith · Webster, US

Key dates

Filing date	Feb 14, 2001
Grant date	Jan 25, 2005
Priority date	—
Expiry date	Apr 7, 2021

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70441
WIPO fieldOptics
WIPO sectorInstruments

Abstract

Photomask manufacture is improved by adding assist bars 320, 340 for isolated features 300. The bars 320, 340 are added at a center to center spacing that corresponds to the center to center spacing for densely packed features. By matching the assist bars to the densely packed features, the combined diffraction pattern of the isolated features is modified to more closely resemble the diffraction pattern of the densely packed features.

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