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:
Nov. 18, 1986
Filed:
Nov. 26, 1984
Osamu Ikenaga, Kawasaki, JP;
Ryoichi Yoshikawa, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A mask inspection apparatus is arranged to compare a measured data signal obtained by optically measuring a photomask with a design data signal representing an integrated circuit pattern so as to inspect defects of the photomask on which the integrated circuit pattern is drawn. To inspect the pattern area and its peripheral area of the mask in one step, a reference signal generator in the mask inspection apparatus is arranged to generate a reference signal containing a predetermined additional data signal representing the peripheral area of the integrated circuit pattern, in addition to the design data signal representing the integrated circuit pattern. The reference signal is compared with the measured data signal of the pattern area and its peripheral area.