A tip-based metrology framework for real-time process feedback of roll-to-roll fabricated nanopatterned structures

Abstract

This paper presents the development of a metrology framework and proof-of-concept tool to perform direct, nanometer-scale topography measurements for real-time process control in the roll-to-roll manufacturing of nanopatterened materials, films, and flexible electronic devices. The system leverages a uniquely compact single chip atomic force microscope (sc-AFM) based on a micro-electromechanical system (MEMS) architecture with custom approach mechanism positioned on a gantry which is actuated by two vertical, double parallelogram flexure mechanism guided two-axis nanopositioners. This probe is situated over a stainless-steel, air bearing supported idler roller and its position dynamically compensated for curvature, eccentricity and surface topography of the roller during web movement through the system from an offline map. The proof-of-concept tool performs a single, 400 μm2, non-contact tapping mode scan with nm height resolution on a flexible, 150 μm × 350 mm polycarbonate substrate every 60 s in a step-and-scan fashion where web movement occurs during each step. The performance of the sc-AFM gantry nanopositioning system is evaluated and a representative nanofeatured flexible material, the wing of a Queen Butterfly, is used as a test artifact to demonstrate the efficacy of the nanometrology data acquired. This capability represents a wholly new method for in-line metrology in roll-to-roll nanomanufacturing.