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. 01, 1977
Filed:
Oct. 12, 1976
Applicant:
Inventors:
Donald E Davis, Wappingers Falls, NY (US);
Millard A Habegger, Boulder, CO (US);
Hannon S Yourke, Poughkeepsie, NY (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2504 / ; 2504 / ;
Abstract
A square shaped beam of charged particles is passed over a registration mark in the surface of a semiconductor wafer. A signal produced by a diode detector that is responsive to backscattered electrons will peak when the beam passes over each of the edges of the registration mark. The signal is differentiated; and the resultant signal is filtered and amplified to provide information regarding the position of the beam with respect to the wafer. If more than one diode detector is used, the signals are added just before or just after the differentiation.