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. 30, 1979
Filed:
Feb. 13, 1978
Drew E Albrecht, Flanders, NJ (US);
Samuel K Doran, Putnam Valley, NY (US);
Michel S Michail, Wappingers Falls, NY (US);
Hannon S Yourke, Poughkeepsie, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and apparatus for applying focus correction to an E-beam or charged particle system to compensate for wafer warp and mask tilt. In an electron beam system including a registration system which measures the position of four registration marks with the beam and calculates the apparent magnification error of a given chip, means are also provided for using magnification and rotation error information to calculate a height error factor and to apply a compensating current to a dynamic focusing coil of the electron beam to move the effective beam focal plane to a position which matches the wafer or mask plane at each chip site.