Patent · US Expired

Method of enhancing clear field phase shift masks with chrome border around phase 180 regions

US6749971B2 · kind B2 · utility

9Cited by
14References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 11, 2001
Grant dateJun 15, 2004
Priority date—
Expiry dateAug 5, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F1/70
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A mask generation method can enhance clear field phase shift masks using a chrome border around phase 180 regions. An exemplary method involves identifying edges of a 180 degree phase pattern, expanding these edges, and merging the expansions with chrome. An alternative method involves oversizing and undersizing phase 180 data, taking the difference, and merging the difference with chrome. The chrome region on the phase mask can improve mask generation by allowing the chrome on the mask to fully define the quartz etch.

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