In-line Monitoring of Ultra-thin Metallic Films on PET Substrates With Sub-nm Resolution

摘要

In-line characterization of industrial web coating processes is crucial for achieving high-quality metallic layers with high thickness uniformity over reel lengths of several tens of thousands of linear meters on polymer substrates. While current measurement techniques, suchas optical transmission or sheet resistance, provide good sensitivity in an intermediate (20-100 nm) to high (100 nm - 1 μm) thickness range, they both lack resolution for metal film thicknesses below 10 nm. We present a new method for characterizing ultrathin ( < 10 nm) metallic films on PET substrates, which provides information on metal thickness as well as morphology. Tests have shown that vacuum coating processes can be characterized in-line with sub-nm resolution during metallization.