Patent Document ID: 20070081170
Application ID: 11635878
Patent Flag: 0

Claim One:
1. A method for optically inspecting and evaluating a semiconductor wafer, the method comprising: identifying a group of semiconductor wafer parameters to be evaluated; providing more than one test pattern on the wafer such that the test patterns have some common physical properties and at least one physical property has different values at, at least two test patterns; providing a theoretical model for the optical response of each test pattern where the model has adjustable unknown parameters; measuring optical responses of the said test patterns; assigning initial estimates to the unknown parameters; applying an iterative search including the steps of: calculating the optical responses of the said test patterns using the said theoretical models, based on the current estimates of the parameters; comparing the sets of calculated and measured optical responses of said test patterns; and updating the estimate of the unknown parameters in a way to minimize a norm of the difference between the measured and calculated optical responses of all test patterns.