Optimal lithographic process control involves a closely coupled combination of test wafer and product wafer characterization. It has been shown in previous work that MPX (Monitor Photo Excursion) optical technology for line-end-shortening metrology of focus and dose provides reliable and low cost product monitor solution. In this work we apply MPX technology to litho cell monitor and control on test wafers. Focus-exposure matrix (FEM) wafers are measured and analyzed automatically on a routine basis. Process window parameters are tracked over time by scanner, including spatial analysis of results across the scanner field such as tilt and curvature. Improvements in litho cell control are discussed.

Date Published: 5 April 2007
PDF: 10 pages
Proc. SPIE 6518, Metrology, Inspection, and Process Control for Microlithography XXI, 65182R (5 April 2007); doi: 10.1117/12.712694

Published in SPIE Proceedings Vol. 6518:
Metrology, Inspection, and Process Control for Microlithography XXI
Chas N. Archie, Editor(s)