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.

Date of Patent:
May. 31, 2005

Filed:

Aug. 19, 2004
Applicant:

Ho-chul Kim, Seoul, KR;

Inventor:

Ho-chul Kim, Seoul, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J001/42 ;
U.S. Cl.
CPC ...
Abstract

A method and system for measuring stray light for use in an exposure apparatus uses an image sensor to be disposed at a wafer level in the exposure apparatus. The stray light is measured by preparing a reference pattern and a measuring pattern on a reticle. The reference pattern includes a light shielding region having first open regions for transmitting light to a center of an active region of the image sensor. The measuring pattern includes a light shielding region having second open regions for transmitting light to a periphery of the active region. A first intensity of light reaching the active region after being filtered by the reference pattern and a second intensity of light reaching the image sensor after being filtered by the measuring pattern are measured. The intensity of the stray light is evaluated by a difference between the first and second light intensities.


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