High-reflectivity DUV mirrors prepared by direct sputtering

We report here high-reflectivity multilayer DBR mirrors in 200–240 nm spectral region. YSZ (yttria-stabilized zirconia), HfO 2 and SiO 2 films were all prepared by direct RF magnetron sputtering. The film annealing conditions were systematically varied to obtain layers with minimal optical absorption. Combining these results, high reflectivity YSZ/SiO 2 and HfO 2 /SiO 2 DBRs were designed and realized with reflectance greater than 99.9%.