Characterizing OPC model accuracy versus lens induced polarization effects in hyper NA immersion lithography
Immersion lithography is extending the lifetime of optical lithography by enabling numerical aperture (NA) greater than unity. Along with scanner hardware improvements, modeling of hyper-NA lithography systems for optical proximity correction (OPC) is also continuing to be necessary in improving photolithography capability. With the use of hyper-NA immersion lithography and polarized illumination, the assumption of scalar optical pupil in optical system modeling may no longer be valid. To fully describe the transmission of any polarization state through the optical system, Jones matrix is necessary. It has been shown that Jones matrix can be described as a combination of apodization loss, birefringence, diattenuation, scalar phase aberrations, and rotation effects. In this work, the impact of such effects on calibration and accuracy of OPC models is characterized in terms of the model fit quality, model predictability, and changes to OPC results.
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