In order to develop low loss, high-performance 193nm Fluoride HR mirrors and anti-reflection coatings, LaF3 and AlF3 materials, used for a single-layer coating, were deposited by a molybdenum boat evaporation process. Various
microstructures that formed under different substrate temperatures and with deposition rates were investigated. The
relation between these microstructures (including cross section morphology, surface roughness and crystalline structure),
the optical properties (including refractive index and optical loss) and mechanical properties (stress) were investigated.
Furthermore, AlF3 used as a low-index material and LaF3 used as a high-index material were designed and deposited for multilayer coatings. Transmittance, reflectance, stress, and the laser-induced damage threshold (LIDT) were studied. It is shown that AlF3 and LaF3 thin films, deposited on the substrate at a temperature of 300 °C, obtained good quality thin films with high transmittance and little optical loss at 193 nm. For multilayer coatings, the absorption mainly comes
from LaF3. Based on these studies, The thickness of 193nm films was controled by a 1/3 baffle with pre-coating
technology. the LaF3/AlF3 AR coantings and HR mirrors at 193nm were designed and deposited. Under the present
experimental conditions, the reflectance of LaF3/AlF3 HR mirror is up to 96%, and its transmittance is 1.5%. the
LaF3/AlF3 AR coanting's residual reflectance is less than 0.14%, and single-sided transmittance is 93.85%. To get a high-performance 193nm AR coating, super-polished substrate is the best choice.