Suppression of cosmic ray backgrounds is crucial to the measurement of neutrino oscillations using the ICARUS detector in the Short-Baseline Neutrino program at the Fermi National Accelerator Laboratory. A Cosmic Ray Tagger subsystem is under construction that provides almost complete solid angle coverage of the liquid argon Time-Projection Chambers. We present the fabrication process and quality control measures for the silicon photomultiplier-based Optical Readout Modules (ORM) that will read out the 860 m2 side-walls constructed from repurposed veto detector modules from the former MINOS experiment.