离子辅助沉积氧化物薄膜的特性分析

【作者】 赵永江；

【导师】 顾培夫；

【作者基本信息】 浙江大学 ， 光学工程， 2005， 硕士

【摘要】 本论文的主要工作是对常规工艺下和离子辅助条件下沉积薄膜的特性进行比较研究，研究的薄膜包括单层膜和多层膜。 1、单层膜的研究 研究的单层膜为SiO₂、TiO₂、Ta₂O₅等氧化物介质薄膜，对比研究了常规工艺下和离子辅助条件下它们的光学特性和机械特性。光学特性涉及折射率、消光系数、波长漂移和聚集密度，发现离子辅助沉积对单层薄膜的光学特性明显改善。机械特性涉及薄膜应力，对离子辅助沉积和常规工艺条件下镀制的薄膜应力进行了试验研究，并对台阶仪测量镀膜前后基板表面的曲率的方法进行了探讨。在基板温度低于100℃时，在离子辅助工艺条件下镀制的TiO₂薄膜应力略大于常规工艺条件下得到的应力；随着薄膜厚度的增加，TiO₂薄膜的应力逐渐减小，从125nm的392 MPa下降到488 nm的30 MPa；离子源阳极电压对薄膜应力影响也较大，在100 V时得到的薄膜应力为164 MPa，当电压升高到190 V时，应力下降到75 MPa；同时也测试了SiO₂和Ta₂O₅单层薄膜的应力，发现Ta₂O₅薄膜的应力特性与TiO₂薄膜的类似，SiO₂的薄膜的应力为压应力。 2、多层膜的研究 采用霍尔源离子辅助沉积（IAD）技术制备了TiO₂／SiO₂、Ta₂O₅／SiO₂窄带干涉滤光片，并与常规沉积条件下制备的样品做了比较，并在各种参数条件下对薄膜样品进行特性分析，发现离子辅助明显地减小了滤光片的光谱漂移（△λ），光谱稳定性得到很大提高。同时发现间隔层对光谱漂移的影响最大，越远离间隔层的膜层，其影响越小；在各种基板温度下，离子辅助工艺技术制备TiO₂／SiO₂窄带干涉滤光片漂移△λ比常规工艺制备的滤光片小8nm左右；在离子辅助工艺条件下，发现随着阳极电流的增加，Ta₂O₅／SiO₂窄带干涉滤光片的中心波长的漂移有明显的下降，从1.4A的10nm下降到2.6A的5nm。同时还分析了TiO₂／SiO₂滤光片的应力特性，发现该滤光片存在零应力的可能。 总之，无论是单层膜还是多层膜，离子辅助样品相对常规工艺样品的光学特性得到明显改善。在离子辅助工艺下，TiO₂薄膜在较高的沉积温度和阳极电压条件下应力较小。更多还原

【Abstract】 In this dissertation, thin films are deposited on K9 glass substrates using an e-beam gun evaporation with low energy oxygen ion assisted deposition (IAD) from an end-Hall ion source. A comparison of the optical and mechanical performance is made between with IAD and without IAD. The researched thin films includes monolayer thin films and multilayer thin films.1. The research of monolayer thin filmsIn the paper, Three monolayer thin films- SiO2、TiO2、 Ta2O5 dielectric thin films are studied. A comparison of the optical and mechanical performance is made between with ion assisted deposition(IAD) and without IAD. The optical performances include the refractive index> the extinction coefficient the packing density and the vacuum-to-air shift . We observe that films deposited with ion assist are much more profitable than those deposited without ion assist;The mechanical performance includes the stress.The stress of thin films deposited with and without IAD was investigated respectively. And the curvature of deformed substrates was measured by profiler. The experimental results shows that TiO2 film stress with IAD is lower than that without IAD below the deposition temperature of 100℃. TiO2 film stress descends with thickness of the films increases .When thickness of the films increases from 125nm to 488nm ,the stress descends from 392 MPa to 30 MPa. And anode voltage of the ion source affects TiO2 film stress .From 100 V to 190 V ,the stress of TiO2 films dropps 89 MPa. The SiO2 and Ta2O5 film stress is researched too. It is found that characteristic of Ta2O5 film stress was similar to that of TiO2 film .And SiO2 film stress is compressive.2. The research of multilayer thin filmsTa2O5/SiO2、 TiO2/SiO2 narrow band interference filters are deposited by IAD with an end-hall ion source. Compared to the specimens produced by conventional process deposition , we discover that spectral shift (△ λ) of the filter is reduced obviously by using IAD .It is found that the space layer has a marked effect onspectral shift, and the change of SiO2 packing density affects spectral shift a lot. The spectral shift of TiO2/SiO2 narrow band interference filters with IAD is less than 8nm compared with the one without IAD under variable deposition temperature. And anode current of the ion source affected the spectral shift . From 1.4A to 2.6A, the spectral shift of Ta2O5/SiO2 narrow band interference filters dropped from 10nm to 5nm. Theoretical calculation was performed and it is found that the stress of TiO2/SiO2 narrow band interference filters may be zero.In conclusion, we observe that both monolayer thin films and multiplayer thin films deposited with ion assist are much more profitable than those deposited without ion assist. TiO2 film更多还原