IC manufacturers are struggling mightily with subwavelength feature sizes as silicon processes descend further into the nanometer realm. To combat the problem, Mentor Graphics tweaked its Calibre suite of resolution enhancement technology (RET) tools in an effort to stay ahead of the curve. Accurate RET modeling of the lithography is pivotal in ensuring pattern fidelity despite the distortions that occur at 100 nm and down. Mentor improved the key model calibration and creation steps addressed in the Calibre VT5 (Variable Threshold, version 5) and TCCcalc (vector, thin-film optical calculations) tools. The enhancements are expected to carry Calibre down to the 45-nm process node. For information, visit www.mentor.com.