Resist model calibration using 2D developed patterns for low-k 1 process optimization and wafer printing predictions

Abstract

We describe a new resist model calibration procedure and its implementation in LithoCruiser™. In addition to the resist calibration, LithoCruiser is used to perform simultaneous optimization for numerical aperture (NA), mask OPC, and illumination profile with built-in manufacturing constraints for ASML illumination diffractive optical elements (DOE). This calibration procedure uses a global optimization algorithm for resist parameter tuning, matching the simulated and measured 2D resist contours at a user-defined multiple CD sampling across the selected developed 2D resist patterns. Using lumped parameter type resist models and vector high-NA simulation engine, this resist calibration procedure showed an excellent calibration capability of max CD error range < ±4nm for the CPL 70nm DRAM patterns. Calibration results for CPL 130nm contact hole patterns are also included in this manuscript. Dependency of the calibrated model parameters on lithography process (i.e., Quasar, C-Quad illumination and at different defocus) and further improvements to a more predictable resist model are discussed.

Investigating a lithography strategy for diagonal routing architecture at sub-100nm technology nodes

“…All the simulations are performed using LithoCruiser [4] from ASML MaskTool. LithoCruiser is an integrated software that analyzes and optimizes scanner performance, illumination source and mask OPC designs [5,6]. Due to the orthogonal metrology cut line limitation in the current version of LithoCruiser, both diagonal test patterns and axis illuminators are rotated 45º in the simulation windows for X Architecture case to obtain process window.…”