Patent · US Expired

Mask for optical projection systems, and a process for its production

US6692875B2 · kind B2 · utility

3Cited by

8References

14Claims

0Family size

Assignee

Infineon Technologies AG · DE

Inventors

Werner Fischer · Heilsbronn, DE
Fritz Gans · Hersbruck, DE
Rainer Pforr · Dresden, DE
Jorg Thiele · Birkenfeld, DE

Key dates

Filing date	Apr 20, 2001
Grant date	Feb 17, 2004
Priority date	—
Expiry date	Sep 13, 2021

Classification

Technology area (CPC G)Physics
CPC primaryG03F1/36
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A mask contains a transparent carrier material on which an opaque region is disposed as an image structure. Also disposed on the carrier material is a semitransparent dummy structure, which is spaced apart from all the image structures and differs from the image structure in terms of transparency and phase rotation. The smallest lateral extent of the dummy structure is then selected to be at least half as large as the smallest lateral extent of the image structure. The semitransparent dummy structure is formed in such a way that it is suitable for increasing the depth of focus of structures that stand individually or at least partially individually, in order thereby to improve the process window of the optical projection.

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