Optical semiconductor characterization and metrology rely heavily on digital camera imaging and its associated optical imaging systems. This work characterizes the performance of a widely used, commercially available camera and compares its performance to that of the art digital camera. It is shown that well corrected lens systems may still exhibit high spatial frequency variations leading to errors of several nanometers for a 1 micrometer pitch measurement. Methods for mapping and correction of such errors are also presented.
Proceedings Title: Proceedings of American Institute of Physics
Pub Type: Conferences
CCD camera, metrology, overlay, self-calibration