Lam Research Corporation
Methods and apparatuses for etch profile matching by surface kinetic model optimization

Abstract:

Disclosed are methods of optimizing a computerized model which relates etched feature profile on a semiconductor device to a set of independent input parameters via the use of a plurality of model parameters. The optimization methods may include modifying the model parameters so that an etch profile generated with the model is such that it reduces a metric indicative of the combined differences between experimental etch profiles resulting from experimental etch processes performed using different sets of values for sets of independent input parameters and computed etch profiles generated from the model and corresponding to the experimental etch profiles. Said metric may be calculated by projecting computed and corresponding experimental etch profiles onto a reduced-dimensional subspace used to calculate a difference between the profiles. Also disclosed herein are systems employing such optimized models, as well as methods of using such models to approximately determine the profile of an etched feature.