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:
Aug. 04, 1992
Filed:
Apr. 05, 1991
Henry I Smith, Sudbury, MA (US);
Erik H Anderson, Lake Pekskill, NY (US);
Mark L Schattenburg, Somerville, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A method of monitoring the travel of a beam of energy on a substrate having a fiducial pattern rigidly fixed relative to the substrate, the pattern embracing an area where the beam can create a useful image with submicron precision. The method includes: adjusting the beam such that the dose delivered by the beam is sufficiently high to generate a signal produced by the interaction of the beam and the fiducial pattern, the signal being representative of the relative position of the fiducial pattern and the travel, the dose being sufficiently low so that the area of the substrate over which the beam passes remains receptive to subsequent creation, with submicron precision, of a useful image; moving the beam across the substrate; detecting the signal produced by the interaction of the beam with the fiducial pattern; and comparing the detected signal with a predetermined signal to provide a position signal representative of the beam travel with submicron precision.