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:
Mar. 13, 2012
Filed:
Dec. 17, 2008
Chien-min Wu, Hsinchu, TW;
Chien-chih Chen, Hsinchu, TW;
Chien-Min Wu, Hsinchu, TW;
Chien-Chih Chen, Hsinchu, TW;
Maxchip Electronics Corp., Hsinchu, TW;
Abstract
A method of measuring a numerical aperture of an exposure machine is described. A control wafer having vernier marks thereon and an aberration mask having pinholes therein are provided, wherein each pinhole corresponds to a vernier mark in position. A lithography process using the exposure machine and the aberration mask is performed to the control wafer, so as to form over each vernier mark a photoresist pattern having the same shape of the illumination pattern of the light source of the exposure machine. The numerical aperture of the exposure machine is then derived from a graduation of the vernier mark corresponding to an outer edge of the photoresist pattern.