Characterizing an exposure tool for patterning a wafer

摘要

Characterizing an exposure tool involves receiving data describing a pattern formed at a wafer. The pattern is formed by illuminating the wafer using an exposure tool, and the data has a scan direction and slit direction. An image field is mapped according to the data to determine an image field error of the data, and the image field error is separated from the data to reduce variation of the data in the scan direction. The data is reduced to the slit direction. Errors associated with the exposure tool are determined from the data in order to characterize the exposure tool.