First results from the Large dynamic range Atomic Force Microscope for overlay metrology

摘要

TNO is developing a novel Large Dynamic Range Atomic Force Microscope (LDR-AFM), primarily but notexclusively designed for sub-nm accurate overlay metrology. The LDR-AFM combines an AFM with a 6 degrees-of-freedom interferometric positioning stage, thereby enabling measurements of sub-nm features on a wafer overmultiple millimeters marker-to-feature distances. The current work provides an overview of recent developmentsand presents the rst results obtained after nal integration of the complete system. This includes results onthe AFM head development, the validated positioning stage performance, the rst AFM images, and long-termstability measurements.