Mask model calibration technologies involving etch effect and exposure effect

Abstract

Methods for jointly calibrating etch and exposure mask process models from etch only data are described. Initially, an etch model and an exposure model may be identified. Subsequently, a combined etch/exposure model may be generated based upon the etch model and the exposure model. Following which, a global optimization process may be performed to calibrate the combined etch/exposure model based upon measured data representing the etch and the exposure effects. With some implementations, the global optimization process is based in part upon a cost function representing the norm of the difference between the simulated mask contours and the measured mask contours. Furthermore, in some implementations, the optimization variable set is the union of the parameter sets corresponding to the etch model and the exposure model individually. Further still, with various implementations, the optimization of based upon the etch parameter set is 'nested' inside an optimization of the exposure parameter set, or, vice versa.