Calibration and application of Gaussian random field models for exposure and resist stochastic in EUV lithography

Abstract

Gaussian random field (GRF) models for EUV lithography (EUVL) exposure and resist process address the randomness of the EUVL process outcomes manifested as line edge roughness, line width roughness or catastrophic failures of pinching, bridging or missing vias. The paper presents the background of GRF models for EUVL processes and discusses the application of such models for fast calculation of success or failure probability of the lithographic process or various stochastic metrics quantifying the stochastic variability of the EUVL process outcome. The paper further concentrates on the approaches to calibration of GRF models. The presented results demonstrate the accuracy of GRF models by comparing the failure probabilities calculated using fast methods against the same probabilities estimated using Monte Carlo trials. The approaches to calibration of GRF EUVL models are demonstrated on experimentally measured data for one of the EUVL processes implemented at IMEC, Belgium.