Patent ID: 7522295
Filing Date: 2009-04-21
Classification: G01N

Abstract:
1. A method of examining structures formed on a semiconductor wafer using consecutive measurements, the method comprising; forming a first structure on a semiconductor wafer; forming a second structure abutting the first structure; measuring a first measured diffraction signal of the first structure using a polarized reflectometer; measuring a second measured diffraction signal of the second structure using the polarized reflectometer, wherein the first and second measured diffraction signals are measured consecutively; comparing the first measured diffraction signal to a first simulated diffraction signal generated using a profile model of the first structure, the profile model having profile parameters that characterize geometries of the first structure; determining one or more features of the first structure based on the comparison of the first measured diffraction signal to the first simulated diffraction signal; converting the second measured diffraction signal to a converted diffraction signal without similarly converting the first measured diffraction signal; comparing the converted diffraction signal to the first simulated diffraction signal or a second simulated diffraction signal generated using the same profile model as the first simulated diffraction signal; and determining one or more features of the second structure based on the comparison of the converted diffraction signal to the first or second simulated diffraction signal.