Patent · US Expired

Photomask having a patterned carbon light-blocking coating

US4704342A · kind A · utility

13Cited by
16References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 2, 1985
Grant dateNov 3, 1987
Priority date
Expiry dateApr 2, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S430/146
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A photomask for use in manufacturing integrated circuits is fabricated by coating a thin film of organic material, generally a solution of a thermally decomposable hydrocarbon, onto a glass plate and heating it in a reducing atmosphere to convert it into carbon. The carbon layer is masked and etched; for example, in an oxygen plasma, to produce the mask.

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