TiO2/Al2O3薄膜的原子层沉积和光学性能分析

采用原子层沉积技术在熔石英和BK7玻璃基片上镀制了TiO2/Al2O3薄膜,沉积温度分别为110℃和280℃。利用X射线粉末衍射仪对膜层微观结构进行了分析研究,并在激光损伤平台上进行了抗激光损伤阈值测量。采用Nomarski微分干涉差显微镜和原子力显微镜对激光损伤后的形貌进行了观察分析。结果表明,采用原子层沉积技术镀制的TiO2/Al2O3增透膜的厚度均匀性较好,Φ50 mm样品的膜层厚度均匀性优于99%;光谱增透效果显著,在1 064 nm处的透过率〉99.8%;在熔石英和BK7基片上,TiO2/Al2O3薄膜在110℃时的激光损伤阈值分别为（6.73±0.47）J/cm2和（6.5±0.46）J/cm2,明显高于在280℃时的损伤阈值。

Optical characteristics of TiO2/Al2 O3 thin films and their atomic layer depositions

Atomic Layer Deposition（ALD） was used to deposit TiO2/Al2O3 films at 110 ℃ and 280 ℃ on quartz and BK7 substrates in this paper.The microstructures of thin films were investigated by an X-ray duffractineter,and the Laser Induced Damage Threshold（LIDT） of samples was measured on a measuring table by a damage test system.Then,the damaged morphologies of the samples were investigated by an Atomic Force Microscope（AFM） and a Nomarski optical microscope,respectively.The results indicate that the films deposited by ALD show better uniformity and transmission,and its uniformity is better than 99% for a Ф50 mm sample and transmission is more than 99.8% at 1 064 nm.Furthermore,the LIDTs of the TiO2/Al2O3 films are（6.73±0.47） J/cm2 and（6.5±0.46） J/cm2 at 110 ℃ on quartz and BK7 substrates,respectively,which is notably better than that at 280 ℃.