Patent · US Active

Lithography mask having sub-resolution phased assist features

US8399157B2 · kind B2 · utility

3Cited by
4References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 23, 2010
Grant dateMar 19, 2013
Priority date—
Expiry dateJul 6, 2031

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F1/28
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Techniques are disclosed for using sub-resolution phased assist features (SPAF) in a lithography mask to improve through process pattern fidelity and/or mitigate inverted aerial image problems. The technique also may be used to improve image contrast in non-inverted weak image sites. The use of SPAF in accordance with some such embodiments requires no adjustment to existing design rules, although adjustments can be made to enable compliance with mask inspection constraints. The use of SPAF also does not require changing existing fab or manufacturing processes, especially if such processes already comprehend phased shift mask capabilities. The SPAFs can be used to enhance aerial image contrast, without the SPAFs themselves printing.

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