Patent Number: 7,088,427

Title: Apparatus and method for high resolution in-situ illumination source measurement in projection imaging systems

Abstract: An in-situ apparatus for high resolution imaging in lithographic steppers and scanners (machines) is described. It comprises a multiple field in-situ imaging objective that images the source directly onto the machine reticle or objective plane. The image on the wafer side of the machine is then recorded electronically or in photo resist. Alternative embodiments create source images at locations before or beyond the wafer plane that can be more conveniently recorded with sensors embedded in the wafer stage chuck.

Inventors: Smith; Adlai H. (Escondido, CA), Hunter, Jr.; Robert O. (San Diego, CA), McArthur; Bruce (San Diego, CA)

Assignee: Litel Instruments

International Classification: G03B 27/72 (20060101)

Expiration Date: 8/08/02018