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:
Oct. 03, 1989
Filed:
May. 20, 1988
Thomas P Donohue, Katonah, NY (US);
Fritz J Hohn, Somers, NY (US);
George A Sai-Halasz, Mount Kisco, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system for the detection of features in a semiconductor wafer for registration. An E-beam scans across an insulator covered with a metallic layer. The high energy electrons penetrate and cause the generation of electron/holes pairs. The drift or migration can be sensed as a current, the intensity of which is a function of the applied field strength. The field strength is in turn varied by the topology of the feature or the presence of a junction in the device. Since the E-beam position is known, registration occurs by correlation with the underlying feature as it is mapped out by sensing variations in current. The feature may be an alignment mark or a device under construction on the wafer.