Real-time optical dimensional metrology via diffractometry for nanofabrication

Surface patterning technologies represent a worldwide growing industry, creating smart surfaces and micro/nanoscale device. The advent of large-area, high-speed imprinting technologies has created an ever-growing need for rapid and non-destructive dimensional metrology techniques to keep pace with the speed of production. Here we present a new real-time optical scatterometry technique, applicable at the mesoscale when optical inspection produces multiple orders of diffraction. We validate this method by inspecting multiple silicon gratings with a variety of structural parameters. These measurements are cross-referenced with FIB, SEM and scanning stylus profilometry. Finally, we measure thermally imprinted structures as a function of imprinting temperature in order to demonstrate the method suitable for in-line quality control in nanoimprint lithography.The authors acknowledge the financial support from the EU project, FLEXPOL (No. H2020-NMBP-PILOT-2016-721062) and the project: Surface and interface reshaped phonon propagation and phonon coupling to photons (SIP). PGC2018-101743-B-I00 (MINECO). The ICN2 is funded by the CERCA programme/Generalitat de Catalunya and is supported by the Severo Ochoa programme of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, grant no. SEV-2017-0706).Peer reviewe