| 摘要 |
A method and structure for optimizing an optical lithography illumination source comprises a shaped diffractive optical element (DOE) interposed between the illuminator and a lens during the exposure of a photoresist layer over a semiconductor wafer. The DOE may, in some instances, increase depth of focus, improve the normalized image log-slope, and improve pattern fidelity. The DOE is customized for the particular pattern to be exposed. Description and depiction of a specific DOE for a specific pattern is provided. Additionally, a pupilgram having a particular pattern, and methods for providing a light output which forms the pupilgram, are disclosed.
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