Evaluation and qualification of lithographic exposure tools is a crucial step in establishing high volume manufacturing processes for IC manufacturers. The data sampling offered by scatterometry can be as dense as that from ECD (electrical CD) for the qualification of the tool. In this paper, the CDs obtained from scatterometry measurements are compared with those obtained by ECD (electrical CD) measurements to show the cross-slit and cross-scan tool characteristics. Since scatterometry is still an order of magnitude slower than ECD, data from various sampling plans will be compared. Another important consideration of this study is to use scatterometry to generate OPC (optical proximity correction) models for the 45nm and 32nm nodes. An accurate measurement of the process to fit the model becomes very crucial in the very deep sub-micron regime. Currently, SEM measurements are performed but they are slow and their precision is not adequate. In this paper, scatterometry measured data will also be compared with SEM data for OPC model fit.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.