中国激光, 2013, 40 (7): 0707001, 网络出版: 2013-06-09
193 nm氟化物薄膜的激光诱导损伤
Laser Induced Damage of Fluoride Coatings at 193 nm
摘要
在ArF准分子激光系统的应用中,光学薄膜元件激光诱导损伤的因素很多,因此在特定模式下分析薄膜损伤机理具有重要意义。采用热蒸发方法分别制备了LaF3和MgF2单层薄膜,以及LaF3/MgF2的半反射薄膜和高反射薄膜,对沉积的薄膜进行了ArF准分子193 nm激光的损伤阈值测量,并采用Nomarski显微镜观察了薄膜的表面缺陷和损伤形貌。实验结果表明,在薄膜的制备过程中,单层LaF3薄膜沉积后表面比较光滑,而MgF2薄膜则有少量的缺陷产生,缺陷随着薄膜层数的增加而逐渐增多。从薄膜的显微观测推断,在此工艺条件下制备的高反射薄膜损伤主要是由于大量缺陷引起。
Abstract
Defects in thin films are one of the most important factors influencing laser induced damage in the thin film components at ArF laser system. In order to analysis the defects of fluoride thin films in wavelength of deep ultraviolet (DUV), LaF3 and MgF2 single layers, LaF3/MgF2 half high reflection (HR) coatings and HR coatings are prepared by thermal evaporation on CaF2, the laser induced damage thresholds (LIDT) at the wavelength of 193 nm for the LaF3 single layer and HR coatings are measured. Nomarski microscope is used to observe the surface defects and damage morphology. It is found that the LaF3 single layer surface becomes more smooth after the preparation, while the MgF2 layer appears a few defects, and the defects increase as the layer number goes up. Based on micrograph of the thin films, lots of defects play a leading role in HR coating damage mechanism at this condition.
常艳贺, 金春水, 李春, 靳京城. 193 nm氟化物薄膜的激光诱导损伤[J]. 中国激光, 2013, 40(7): 0707001. Chang Yanhe, Jin Chunshui, Li Chun, Jin Jingcheng. Laser Induced Damage of Fluoride Coatings at 193 nm[J]. Chinese Journal of Lasers, 2013, 40(7): 0707001.