Patent ID: 7049156
Filing Date: 2006-05-23
Classification: G01B,G01N,G06K,H01L

Abstract:
1. A method for determining a value for at least one parameter associated with a wafer comprising: receiving observed reflectivity data from a surface of a wafer; obtaining calculated reflectivity data for the wafer, said calculated reflectivity data being a function of at least one parameter; transforming one of the observed reflectivity data and the calculated reflectivity data; transforming the other of the observed reflectivity data and the calculated reflectivity data to coincide with the transformed one of the observed reflectivity data and the calculated reflectivity data; finding agreement between the transformed one of the observed reflectivity data and the calculated reflectivity data, and the transformed other of the observed reflectivity data and the calculated reflectivity data on the at least one parameter; and determining a value for the at least one parameter based on the agreement.