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. 17, 2008
Filed:
Sep. 15, 2005
Applicant:
Sachiko Yabe, Tokyo, JP;
Inventor:
Sachiko Yabe, Tokyo, JP;
Assignee:
Oki Electric Industry Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 27/52 (2006.01); G03B 27/32 (2006.01);
U.S. Cl.
CPC ...
Abstract
A shot of a focus-monitoring mark is provided on a wafer at a first focus position (ΔDF) defocused from a second focus position (Fk) by a certain amount to measure a dimension (La) of the focus-monitoring mark. The actual focus position (F) of the defocused shot is calculated by the measured dimension (La) and the defocused direction of the defocused shot, using a calibration quadratic function curve (). The difference (F−ΔDF) between the actual focus position and the defocused amount represents the magnitude and direction of deviation of the actual focus position from the optimum focus position.