METHODS AND APPARATUSES FOR ETCH PROFILE OPTIMIZATION BY REFLECTANCE SPECTRA MATCHING AND SURFACE KINETIC MODEL OPTIMIZATION

摘要

Disclosed are methods for optimizing a computer model to associate an etching profile of a feature on a semiconductor substrate with a set (A) of independent input parameters through a use of a plurality of model parameters (B). In some embodiments, the methods can include a step of correcting at least one value of (B) so as to reduce a metric representing differences between a calculated reflection spectrum generated from the computer model for one or more sets of values of (A) and a corresponding experimental reflection spectrum. In other embodiments, a step of computing the metric can include the operations of projecting the experimental reflection spectrum corresponding to the calculated reflection spectrum onto a reduced dimension subspace, and calculating a difference between reflection spectrums when projected onto the subspace. Also, described are etching systems which implement such optimized computer models.