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:
Jan. 19, 1999
Filed:
Jun. 27, 1997
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method of manufacturing a mask in which laser radiation is projected to a mask substrate of silicon and a supporting frame of heat resisting glass, while a voltage of about 1000-10000 V is applied between the mask substrate and the supporting frame. Cooling water is caused to flow to suppress temperature rise due to the irradiation, to maintain the mask substrate and the supporting frame at a predetermined normal temperature (about the mask temperature in a lithographic pattern transfer process). The light projecting step is performed for a period not shorter than 10 minutes whereby anodic bonding of the mask substrate with the supporting frame is achieved. This prevents a shift of the mask pattern and/or deformation of the mask substrate, and it assures the manufacture of a high precision mask.