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. 18, 1985
Filed:
Aug. 11, 1982
Applicant:
Inventors:
George Maheras, Fort Collins, CO (US);
Hubert O Hayworth, Fort Collins, CO (US);
Assignee:
NCR Corporation, Dayton, OH (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356399 ;
Abstract
Various structural patterns of alignment keys particularly suited for aligning masks and wafers during the fabrication of semiconductor devices. Each alignment key includes an orthogonal arrangement of bar-shaped segments. The relative dimensions of the mask and wafer alignment keys ensure a partial overlap and coaxial positioning of the bar-shaped segments when the keys are fully aligned. Precise optical alignment of the mask and wafer keys is evidenced by visually perceived edge diffraction effects. The invention also encompasses a systematic method for aligning representative structural patterns.