Patent · US Expired

Method and apparatus for correcting transparent defects on a photomask

US4444801A · kind A · utility

41Cited by
3References
40Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 12, 1982
Grant dateApr 24, 1984
Priority date
Expiry dateJan 12, 2002

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05K3/225
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus for correcting transparent defects on a photomask are disclosed. A metal-organic complex solution is applied to a transparent defect portion and its periphery on the photomask. The transparent defect portion is then exposed to a visible ray or ultraviolet ray to deposit a metal, a metal oxide or a composition thereof, while the light transmission quantity through the transparent defect portion is measured. After the measurement falls below a predetermined level relative to the quantity of the transmitted light at the start of exposure, the exposure is terminated to thereby complete the correction of the transparent defects.

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