An overview of the challenges encountered in imaging device-sized features using optical techniques recently developed in our laboratories is presented in this paper. We have developed a set of techniques we refer to as scatterfield microscopy which allows us to engineer the illumination in combination with appropriately designed metrology targets. The techniques have previously been applied to samples with sub-50 nm sized features having pitches larger than the conventional Rayleigh resolution criterion which results in images having edge contrast and elements of conventional imaging. In this paper we extend these methods to targets composed of features much denser than the conventional Rayleigh resolution criterion. For these applications, a new approach is presented which uses a combination of zero order optical response and edge-based imaging.
Proceedings Title: Proceedings of SPIE
Conference Dates: February 19-24, 2006
Conference Location: San Jose, CA
Conference Title: Metrology, Inspection, and Process Control for Microlithography XX
Pub Type: Conferences
imaging device-sized features, optical techniques