Modeling and Performance Metrics for Longitudinal Chromatic Aberrations, Focus- drilling, and Z-noise; Exploring excimer laser pulse-spectra

The combined impact of longitudinal chromatic aberrations, focus-drilling, and Z-noise on several lithographic performance metrics is described. After review, we investigate an improved method for simulating the lithographic behavior of longitudinal chromatic aberrations stemming from the finite bandwidth of excimer laser pulse-spectra using PROLITH TM v. 9.3.3. Additionally, we explore two methods for modeling the lithographic improvements related to focus-drilling and new PROLITH functionality for modeling the effects of Z-noise. Our case studies involve reinvestigating the RELAX process and providing a framework for accurate lithographic simulation using machine specific pulse-spectral data, modified Lorentzian, and Gaussian models. After presentation and analysis, we discuss potential applications including methods for improved focus budgets and improved mask design.