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:
Mar. 02, 1999
Filed:
Dec. 27, 1991
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical exposure mask for patterning an optical beam comprises an etching stop layer of a material that is substantially transparent with respect to the optical beam, a transparent pattern provided on one of upper and lower major surfaces of the etching stop layer, and an opaque pattern provided on one of the upper and lower major surfaces of the etching stop layer for patterning the optical beam, wherein the material for the etching stop layer is selected from a group essentially consisted of Al.sub.2 O.sub.3, MgO and a mixture thereof, and the etching stop layer has an etching rate that is substantially smaller than the etching rate of a material forming the transparent pattern for any of dry and wet etching processes.