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:
Jun. 12, 2001
Filed:
Mar. 22, 1999
Rodney Arthur Kendall, Ridgefield, CT (US);
Gary J. Johnson, Wappingers Falls, NY (US);
David J. Pinckney, Danbury, CT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
In a particle beam lithography system, focus adjustment is controlled by a measurement of the gap between the workpiece being processed and a reference surface, such as the bottom surface of the focus lens, using a pair of capacitive sensors mounted on an arm that rotates to place one sensor on the beam axis to measure the workpiece height and the other displaced from the beam aperture to measure the height of the reference surface. The sum of the two readings is constant (for a given gap dimension), so that the accuracy of the measurement is not affected by the position of the arm within the gap.