Patent · US Expired

Attenuated embedded phase shift photomask blanks

US6858357B2 · kind B2 · utility

2Cited by
3References
47Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 8, 2003
Grant dateFeb 22, 2005
Priority date
Expiry dateSep 16, 2023

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/265
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

An attenuating embedded phase shift photomask blank that produces a phase shift of the transmitted light is formed with an optically translucent film made of metal, silicon, nitrogen or metal, silicon, nitrogen and oxygen. A wide range of optical transmission (0.001% up to 20% at 193 nm) is obtained by this process. A post deposition process is implemented to obtain the desired properties (stability of optical properties with respect to laser irradiation and acid treatment) for use in industry. A special fabrication process for the sputter target is implemented to lower the defects of the film.

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