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:
Jun. 03, 2003
Filed:
Apr. 13, 2001
Applicant:
Inventors:
Adlai Smith, San Diego, CA (US);
Bruce McArthur, San Diego, CA (US);
Robert Hunter, Jr., San Diego, CA (US);
Assignee:
Litel Instruments, San Diego, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B 9/00 ;
U.S. Cl.
CPC ...
G01B 9/00 ;
Abstract
A projection lens distortion error map is created using standard overlay targets and a special numerical algorithm. A reticle including a 2-dimensional array of standard overlay targets is exposed several times onto a photoresist coated silicon wafer using a photolithographic stepper. After exposure, the overlay targets are measured for placement error using a conventional overlay metrology tool. The resulting overlay error data is then supplied to a software program that generates a lens distortion error map for the photolithographic projection system.