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. 22, 2014
Filed:
Feb. 09, 2010
Adlai H. Smith, Escondido, CA (US);
Robert O. Hunter, Jr., Snowmass Village, CO (US);
Adlai H. Smith, Escondido, CA (US);
Robert O. Hunter, Jr., Snowmass Village, CO (US);
Litel Instruments, San Diego, CA (US);
Abstract
A method and apparatus for determining the state of the lens transmittance of an optical projection system are described. A lens or imaging objective transmission is determined as a function of exit pupil transverse direction cosine (nx,ny) at multiple field points thereby providing a more complete analysis and correction of a photolithographic exposure system. The entrance pupil of a projection imaging system is uniformly illuminated and the angular dependence of transmission through the imaging system as a function of exit pupil direction cosines is determined. The illumination source includes a light conditioner with an in-situ illumination structure (ISIS), which is an optical structure that can provide uniform illumination of the system's entrance pupil.