Patent · US Expired

Multiple density mask and fabrication thereof

US4770947A · kind A · utility

5Cited by
4References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 2, 1987
Grant dateSep 13, 1988
Priority date
Expiry dateJan 2, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/12944
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A multi-layer structure that includes a transparent dielectric substrate, a layer of a nickel-containing steel alloy, and a layer of copper and/or chrome.

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