Exposure field matching of multiple step-and-scan systems to multiple step-and-repeat systems

Abstract

The introduction of DUV step-and-scan exposure tools into a mix-and-match manufacturing environment with traditional i-line step-and-repeat systems has presented many unique challenges to lithographic process engineers. One of these challenges has been the development of a reliable method for characterizing and optimizing intrafield pattern overlay registration. A method is proposed here that utilizes metrology and analysis techniques that have been proven for traditional homogeneous manufacturing environments. Enhancements to these traditional techniques that are designed to manage the special circumstances related to heterogeneous system matching between step-and-scan and step-and-repeat systems are described. Particular attention is paid to the characterization of the A-B-C matching of exposure field (lens) signatures. Results of this method applied to a representative manufacturing environment are presented and discussed.