摘要 |
A lithographic system including a light source configured to provide a light beam, a mask stage configured to hold a mask having a mask pattern, a wafer stage having a surface configured to hold a wafer having a plurality of dies, and an illumination monitor having a receiver disposed at the surface of the wafer stage and a polarimeter. A projection system is configured to shape and direct the light beam via the mask pattern to form an exposure beam and to individually expose each die with the exposure beam, and is configured to shape and direct the light beam to form a monitor beam and to expose the receiver with the monitor beam. The receiver is configured to communicate the monitor beam to the polarimeter which, based on the monitor beam, is configured to provide an illumination signal representative of properties of the light beam as it passes through the lithographic system.
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