Optical Angular Scatterometry 8.0-kHz for In-line Nano-Manufacturing

Metrology is fundamental during manufacturing processes. This research focuses on an in-line metrological tool that can be used during roll-to-roll (R2R) fabrication of nano-size structures. Optical angular scatterometry is a fast, non-contact, non-destructive nanoscale metrology tool that is proven to characterize periodic structures during real-time nano manufacturing. In this presentation, we demonstrate an optical angular scatterometry set up that operates at speeds commensurate with R2R tooling by using 45° off-axis parabolic mirrors. Angular scan scatterometry systems have been widely exploited for off-line, and in-line metrology. Four different wavelengths (244, 405, 633, 982 nm) were used to characterize wire-grid polarizer and photoresist gratings proving that angular scatterometry is capable for nano-metrology off-line applications with CD down to 20 nm period for wire-grid-polarizers and 24 nm periodic photoresist structures. Also, we have reported in-line capabilities by scanning the 0th order reflection as a function of incident angle by using a 2-kHz resonant scanner and 90° off-axis parabolic optics. Similarly, our newest in-line set-up scans 0th order reflection as a function of incident angle, but the angular range and the scanning speed were improved. Using an 8-KHz resonant scanner, 45° off-axis parabolic mirrors, and a total redesign layout, the new in-line angular scatterometer offers scanning and characterization capabilities for R2R nano-scale fabrication processes. Our current in-line scatterometer offers high-speed, non-contact, real-time, non-destructive capabilities for R2R systems with web speed up to ~50 cm/s. Our design can be easily accommodated in electronic manufacturing systems.