Research into characterization of wafer stepper systems has been done primarily by analyzing a series of wafer exposures. This method does not allow for easy separation of the effects of the exposure system and the resist processing system. In addition, determination of the transfer characteristics of projection lithographic lenses is typically done before the lens system is installed into the wafer stepper system. A method is presented which allows for the in-situ determination of the modulation transfer function. This method separates the processing effects from those of the exposure system. Scattered light from a polys il icon edge is shown to be in close agreement with the theoretical MTF as calculated by SAMPLE. Focus effects on the resultant MTF curves are demonstrated. A comparison between single and multiple scattering lines demonstrates that there is little difference in the MTF curves.
Library of Congress Subject Headings
Semiconductor wafers--Design--Analysis; Microlithography; Transfer functions
Department, Program, or Center
Chester F. Carlson Center for Imaging Science (COS)
Carlson, Steven D., "Investigation of an in-situ method for determining the modulation transfer function and its applications in a microlithographic wafer stepper" (1990). Thesis. Rochester Institute of Technology. Accessed from
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