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. 19, 1986
Filed:
Oct. 12, 1983
Applicant:
Inventors:
Armand P Neukermans, Palo Alto, CA (US);
Steven G Eaton, Palo Alto, CA (US);
Assignee:
Varian Associates, Inc., Palo Alto, CA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
324 / ; 148D / ;
Abstract
An aligner for aligning a mask and a wafer during photolithography of a semiconductor chip uses detection of the differential capacitance between two sets of conductive fingers on the mask and ridges on the wafer. An A.C. signal is applied to the ridges and the phase or amplitude of the signals coupled to the two sets of fingers is detected and compared. A shield is positioned between the ridges and the fingers to ensure that coupling occurs only between desired portions of the ridges and the fingers.