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:
Feb. 08, 2000
Filed:
Oct. 20, 1998
Koichi Sogawa, Kobe, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An overlay target for the precision measurement is provided, including a substrate box formed over or in a substrate and a top box formed over the substrate box 13 and the substrate. The substrate box is of square with its side of 10 microns long. The top box is formed as a square opening composed of a layer of either a positive or negative type photo-resist with its side 10 microns long. These boxes are disposed rotated by 45.degree. with respect to each other and the centers of the box marks are aligned during process steps to coincide with each other to thereby result in a minimal amount of displacement, if any, between the centers. Following the measurements of the lengths of the sections a, b, c and d, which are defined by the overlap between the top and substrate boxes on the confronting sides, amounts of displacement between the centers of the two boxes are determined using the relationships, X.sub.reg =(b-a)/4 and Y.sub.reg =(d-c)/4.