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:
Jul. 26, 2022
Filed:
Nov. 27, 2020
Applicant:
Kla Corporation, Milpitas, CA (US);
Inventor:
Xiumei Liu, Fremont, CA (US);
Assignee:
KLA Corporation, Milpitas, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N 21/95 (2006.01); G06T 7/00 (2017.01); G01N 21/88 (2006.01);
U.S. Cl.
CPC ...
G01N 21/9501 (2013.01); G01N 21/8806 (2013.01); G06T 7/0004 (2013.01); G06T 2207/30148 (2013.01);
Abstract
A beam of light is directed from a light source at a wafer on a chuck. The beam of light is reflected off the wafer toward a 2D imaging camera. Movable focus lenses in the path of the beam of light can independently change the illumination conjugate and the collection conjugate. A structured mask in an illumination path can be used and the beam of light can be directed through apertures in the structured mask. A gray field image of a wafer in a zone without direct illumination is generated using the 2D imaging camera and locations of defects on the wafer can be determined using the gray field image.