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:
Jul. 11, 2000

Filed:

Dec. 16, 1998
Applicant:
Inventor:

Young-chang Kim, Seoul, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01B / ;
U.S. Cl.
CPC ...
356401 ; 250548 ; 355 53 ; 355 77 ; 356372 ;
Abstract

A focus test mask for a projection exposure system, a focus monitoring system using the same, and a focus monitoring method include a transparent substrate and a focus test pattern formed on the substrate. The focus test pattern includes a first light shielding pattern and a second light shielding pattern placed inside the first light shielding pattern. Both light shielding patterns have fine protruding patterns arranged along edges of respective first and second closed geometric shapes defining the light shielding patterns. The focus test pattern projected onto the surface of the object allows quantitative measurement of the optimal focuses of the projection exposure system. By using the focus test mask for a projection exposure system, the optimal focuses of the projection exposure system can be periodically measured easily and precisely.


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