The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 1996
Filed:
Nov. 09, 1993
Abstract
A phase shift photomask is produced in the following manner. Before or after a light-shielding pattern is formed on a substrate, a transparent film serving as a phase shifter is coated onto the substrate, and the transparent film in a photomask-pattern-forming area exluding the peripheral area of the substrate is irradiated with energy rays. The irradiated portion of the transparent film is thus solidified. The unsolidified portion of the transparent film is removed by etching. A phase shifter pattern is thus formed on the substrate excluding the peripheral area of the substrate. Since the phase shifter pattern is not exposed at the peripheral area of the substrate, a dust which is usually made when the phase shifter pattern formed in this area cracks or peels off the substrate is not made. The number of defective photomasks to be produced can thus be reduced.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile