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. 08, 2005
Filed:
Mar. 08, 2002
Youling Lin, Richardson, TX (US);
A. Kathleen Hennessey, Richardson, TX (US);
Yongqiang Liu, Plano, TX (US);
Yonghang Fu, Plano, TX (US);
Masami Yamashita, Kumamoto, JP;
Ichiro Shimomura, Kikuyo-machi, JP;
YouLing Lin, Richardson, TX (US);
A. Kathleen Hennessey, Richardson, TX (US);
Yongqiang Liu, Plano, TX (US);
Yonghang Fu, Plano, TX (US);
Masami Yamashita, Kumamoto, JP;
Ichiro Shimomura, Kikuyo-machi, JP;
ISOA, Inc., Richardson, TX (US);
Abstract
A system and method for performing optical inspection of structures on the surface of a semiconductor wafer. The wafer surface is illuminated with a polychromatic light source. A multiple-charged couple-device (CCD) camera is positioned to capture light diffracted by the structures on the wafer surface at the first order of diffraction. The captured light is then separated into a plurality of component wavelengths which are directed onto the CCDs. A digital filter creates a plurality of digitized diffractive images of the wafer surface at different component wavelengths. The diffractive images may be integrated and analyzed to detect defects in the structures, or may be, analyzed individually. An image at a particular wavelength may be selected and analyzed by using the known grating pitch of the structures to calculate the wavelength.