Thermal stability of high-reflectance La/B-based multilayers for 6.x nm wavelength

摘要

We have investigated the thermal stability of La/B-based (LaN/La/B) multilayer structures with partial-layer nitridation of La, a method shown earlier to result in enhanced reflectivity. The structures were annealed in the temperature range 100-500 °C for 70 h. They showed period drifts by 0.005 nm at 100 °C to 0.06 nm at 500 °C. A reflectivity loss of more than 2% was only observed after annealing above 300 °C. The study included separate investigation of B-on-LaN and LaN-on-La-on-B interfaces.