HfO2中ZrO2含量对266nm HfO2/SiO2多层膜反射率的影响

用两种不同纯度的HfO2材料与同一纯度的SiO2材料组合，沉积Λ／4规整膜系(HL)^11H形成266nm的紫外反射镜，发现反射率相差0．7％左右。用X光电子能谱法分析了高反膜中表层HfO2中的成分，发现ZrO2的含量相差一个数量级左右。为确定形成这种差别的原因，用辉光放电质谱法测定了这两种HfO2材料中锆(Zr)及其钛(Ti)、铁(Fe)的含量，发现Zr是其中的最主要的杂质，两种HfO2材料中Zr含量有一个数量级的差别。说明在266nm波段，HfO2中ZrO2的含量会对HfO2／SiO2高反膜的反射率造成影响。根据HfO2单层膜的光谱曲线，推算出了这两种材料的消光系数的差别，并用Tfcalc膜系设计软件进行理论和镀制结果的模拟，得到与实验测试一致的结果。

Effect of ZrO2 in HfO2 on the Reflectance of HfO2/SiO2 Multilayer for Deep Ultraviolet Mirrors

HfO 2/SiO 2 multilayer reflective mirrors were deposited on BK7 substrates by E-beam evaporation. Two starting materials of HfO 2 with different purities were combined with the same SiO 2 respectively, their reflectance had a difference of 7%. X-ray photoelectron spectroscopy (XPS) survey of the surface HfO 2 layers of the two kinds of multilayer thin films shows that they have a difference of one magnitude order in ZrO 2 content. To explore the reason to such a result, the massive percent of impurity Zr, Ti and Fe in the two kinds of HfO 2 was investigated with Glow Discharge Mass Spectrum technology. From that it can be seen that ZrO 2 was the main extraneous component in the materials and responsible for the reflectance loss. It can be concluded that the content of ZrO 2 in HfO 2 will influence the reflectance of HfO 2/SiO 2 multilayer thin film at the spectrum of 266 nm. In addition, the extinction coefficients of the two kinds of HfO 2 thin film were obtained from fitting the transmission spectra of the single layer coatings. With the calculated optical constants, the theoretical reflectance for the corresponding film stack agreed well with the measured result.