Patent attributes
Provided are scatterometry techniques for evaluating a 3D diffracting structure. In one embodiment, a method involves providing a 3D spatial model of the diffracting structure and discretizing the model into a 3D spatial mesh. The method includes approximating 3D fields for each element of the 3D mesh using 3D spatial basis functions and generating a matrix including coefficients of the 3D spatial basis functions approximating the fields. The coefficients of the 3D spatial basis functions are computed and used in computing spectral information for the model. The computed spectral information for the model is compared with measured spectral information for the diffracting structure. If the model is a good model fit, the method involves determining a physical characteristic of the diffracting structure based on the model of the diffracting structure.
