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. 17, 1998
Filed:
Nov. 13, 1996
Rainer Butsch, Fairport, NY (US);
William A Enichen, Poughkeepsie, NY (US);
Michael S Gordon, Somers, NY (US);
John G Hartley, Fishkill, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for monitoring resist charging in an electron beam lithography system is disclosed. The method involves the use of a reference plate (REFP) registration scheme in which a resist-coated REFP having registration marks on a substrate is prepared and scanned. The scanning process includes the deposition of an amount of charge on the surface. Then the REFP is coated with a resist to be tested and scanned again. The difference between the two scans is calculated. Preferably, each scan is performed first with the stage moving in a forward-ordered serpentine path in the tool to determine the perceived positions of the registration marks and then in a backward-ordered serpentine path. As the tool's stage moves from field to field, a small charge is deposited on the REFP to simulate the effect of a writing process. The difference between the forward and reverse scan position measurements is then determined. As any intrinsic positional errors in measurement will cancel out, the forward/backward error provides a monitor of the magnitude of resist charging.