Influence of deposition parameters on residual stress of YbF_3 thin film

摘要

YbF_3 was proposed as a substitute for ThF_4 in anti-reflection or reflection coatings for the infrared range, and the residual stress of YbF_3 thin film using APS plasma ion assisted deposition(PIAD) was studied. From the results, we found the anode voltage of PIAD has a large effect on the residual stress of YbF_3 thin film, and the refractive index of YbF_3 produced with PIAD was higher than without it, with a possible reason close to packing density. Finally, we produced multi-layer reflection coating on a 260mm diameter mono-crystalline silicon substrate. Its surface contour was approximately 0.240 λ ( λ =632.8nm), and the absorption was lower than 200ppm, which can satisfy the practical requirement.