热蒸发与离子束溅射制备LaF_3薄膜的光学特性  

Optical properties of LaF_3 thin films prepared by thermal evaporation and ion beam sputtering

作　　者：才玺坤[1] 张立超[1] 梅林[1] 时光[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,吉林长春130033

出　　处：《中国光学》2014年第5期808-815,共8页Chinese Optics

基　　金：国家重大科技专项(02专项);基金资助项目(No.2009ZX02205)

摘　　要：研究了钼舟热蒸发工艺和离子束溅射方法制备的单层LaF3薄膜的特性。首先,采用分光光度计测量了LaF3薄膜的透射率和反射率光谱,使用不同模型拟合得出薄膜的折射率和消光系数。然后,采用应力仪测量了加热和降温过程中LaF3薄膜的应力-温度曲线。最后,采用X射线衍射仪测试了薄膜的晶体结构。实验结果表明,热蒸发制备的LaF3(RH LaF3)存在折射率的不均匀性,在193 nm,其折射率和消光系数分别为1.687和5×10-4,而离子束溅射制备的LaF3(IBS LaF3)折射率和消光系数分别为1.714和9×10-4。两种薄膜表现出相反的应力状态,RH LaF3薄膜具有张应力,而IBS LaF3具有压应力,退火之后其压应力减小。热蒸发制备的MgF2/LaF3减反膜在193 nm透过率为99.4%,反射率为0.04%,离子束溅射制备的AlF3/LaF3减反膜透过率为99.2%,反射率为0.1%。To meet the requirements for different practical applications , we investigate the properties of single LaF3 layer deposited by resistive heating Mo-boat（RH） and ion beam sputtering（IBS） in this paper.First, transmittance and reflectance spectra of LaF 3 thin films were measured by an UV-visible spectrophotometer , and the refractive indexes and extinction coefficients were obtained by using different models .Second , stress-temperature curves of LaF 3 thin films during heating and cooling cycles were carried out by a stress measure-ment system.Finally, the X-ray diffraction（XRD） was used to characterize the microstructure of LaF 3 layers. Experimental results indicate that LaF 3 thin film fabricated by thermal evaporation （ RH LaF3 ） had an inhomo-geneous refractive index;the refractive index and extinction coefficient at 193 nm are 1.687 and 5 ×10 -4 for RH LaF3 , and 1.714 and 9 ×10 -4 for IBS LaF3 , respectively.RH LaF3 and IBS LaF3 exhibited inverse stress status.RH LaF3 had a tensile stress and IBS LaF 3 showed a compressive stress , which decreased after annea-ling.The transmittances are 99.4%and 99.2%for RH deposited MgF2/LaF3 AR coating and IBS deposited AlF3/LaF3 AR coating, and the corresponding measured reflectances are 0.04%and 0.1%,respectively.

关 键 词：薄膜 LAF3 热蒸发 离子束溅射 应力 减反膜 

分 类 号：O484.41[理学—固体物理]