Ability to predict process behavior under defocus has until now relied on explicit calculations, which while accurate, cannot be realistically used in full-chip optical and process correction strategies due to the long run times. In this work, we have applied a vector model for the optics, and a compact model for the resist development process. Simulations with these models are fast enough to be the basis of full-chip OPC. We verify this strategy with an independent set of measurements, and compare it to current lithographic process fitting strategies. The results indicate that by describing optical processes as accurately as possible, the model accuracy improves over a wider range of defocus conditions when compared to the traditional calibration method.As long as the calibration process successfully decouples optical and resist effects, relatively simple resist models deliver excellent accuracy within the noise level of the metrology measurements. Our data are based on onedimensional and two-dimensional results using a 193nm system using 0.75 NA and off axis illumination with 6% attenuated phase shift mask. In all cases, a wide variety of sub-resolution assist feature rules were used in order to further test the ability of the models to predict various optical and resist environments.

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As 6% attenuated phase shift masks (PSM) become commonly used in ArF advanced lithography for the 90nm Technology and mass production to print lines/ spaces as well as contacts, the specification and control of the phase angle and the width of the distribution of phase angles becomes critical to maintain the quality of the lithography process. The influence of the mean phase angle and the width of the distribution of phase angles on the best focus, the through pitch behavior and uniformity of the critical dimension (CD uniformity) has been studied experimentally using a 6% attenuated PSM whose phase angle has been affected by several reticle cleans. The results are consistent with aerial image simulations. Independent specifications for the mean phase angle and the width of the distribution of phase angles have been derived and could be applied for the production of masks in the future.

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