摘要
针对大口径光学元件溅射沉积膜厚不均匀的问题,采用离子束溅射平坦化层来改善光学元件表面粗糙度.利用膜厚检测仪测出光学元件沉积面上的中心区域以及各边缘区域的膜厚值,计算离子束在光学元件中心与边缘驻留时间比,并通过MATLAB拟合驻留时间分布规律,根据所得的数据进行逐级修正.实验结果表明,当驻留时间比优化为-26.6%时,可以实现在直径300~600mm大口径的光学元件上均匀镀膜,以熔石英表面上镀硅膜为例,溅射沉积6h,表面膜厚为212.4±0.3nm,薄膜均匀性达到0.4%.
Aiming at the problem that nonuniform thickness of sputter deposited film on large-caliber optical components,the ion beam sputtering planarization layer was used to improve the surface roughness of the optical elements.The film thickness of the center and edge of optical elements depositing surface was measured by the film thickness detector,and the dwell time ratio of the center to edge was calculated.The dwell time distribution was fitted by MATLAB,and the value was corrected by the obtained data step by step.The experimental results show that,when the dwell time ratio is revised to-26.6%,uniform film can be achieved on optical elements with a diameter of 300~600mm.Taking a Si film on the surface of fused silica as an example,the experiment is carried out for 6h,the film thickness is 212.4±0.3nm,and the film uniformity can reach up to 0.4%.
引文
[1] CAI Xi-kun,ZHANG Li-chao,SHI Guang,et al.Low stress ultraviolet optical thin film prepared by ion beam sputtering[J].Chinese Optics,2016,9(6):649-655.才玺坤,张立超,时光,等.离子束溅射制备低应力深紫外光学薄膜[J].中国光学,2016,9(6):649-655.
[2] BUNDESMANN C,LAUTENSCHLGER T,THELANDER E,et al.Reactive Ar ion beam sputter deposition of TiO2,films:influence of process parameters on film properties[J].Nuclear Instruments&Methods in Physics5-2001310Research,2017,395:17-23.
[3] HUANG Jun-jun,GUI Cheng-mei,DING Ming,et al.Effect of assisted-ion-beam gases on the structure of amorphous silicon thin films prepared by ion-beam-assisted sputtering[J].Materials Science Forum,2016,852:1102-1107.
[4] KIONTKE S,ALLENSTEIN F.Ion-beam figuring(IBF)for high-precision optics becomes affordable[C].SPIE,2010,7786:77860F.
[5] ARKWRIGHT J,BURKE J,GROSS M.A deterministic optical figure correction technique that preserves precisionpolished surfacequality[J].Optics Express,2008,16(18):13901-13907.
[6] TANG Wa.Research on removal model and technology for ion beam figuring large aspherical mirror[D].Changchun:Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,2016.唐瓦.离子束抛光大口径非球面去除模型与工艺研究[D].长春:中国科学院长春光学精密机械与物理研究所,2016.
[7] FU Xiu-hua,YANG Yong-liang,LIU Guo-jun,et al.Study on the uniformity of diamond-like carbon films on a large hood[J].Infrared and Laser Engineering,2013,42(1):181-184.付秀华,杨永亮,刘国军,等.大面积头罩上类金刚石薄膜均匀性研究[J].红外与激光工程,2013,42(1):181-184.
[8] ORTIZ T,CONDE C,KHAN T M,et al.Thickness uniformity and optical/structural evaluation of RF sputtered ZnO thin films for solar cell and other device applications[J].Applied Physics A,2017,123(4):280-286.
[9] CHEN Gui-yang,XIE Xu-hui,ZHOU Lin,et al.Study on the removal function and stability of radiofrequency ion source in optical processing[J].Aeronautical Precision Manufacturing Technology,2016,52(5):19-22.谌贵阳,解旭辉,周林,等.光学加工射频离子源的去除函数与稳定性研究[J].航空精密制造技术,2016,52(5):19-22.
[10] ZHAO Miao,LEI Guang-jiu,LI Ming,et al.Analysis of beam characteristics of the radio frequency ion source[J].Nuclear Fusion and Plasma Physics,2018,38(2):152-157.赵淼,雷光玖,李明,等.射频离子源束流特性分析[J].核聚变与等离子体物理,2018,38(2):152-157.
[11] GUO Cheng-jun,PEI Ning,WANG Da-sen,et al.The technique of ion beam etching polishing[J].Applied Mechanics&Materials,2013,395-396:1066-1070.
[12] MENG Meng,WU Wen-ge,ZHANG Yong,et al.Optimization of process parameters of sputtered thin films based on response surface methodology[J].Tool Technology,2017,51(7):24-27.孟萌,武文革,张勇,等.基于响应曲面法的溅射沉积薄膜工艺参数优化[J].工具技术,2017,51(7):24-27.
[13] LI Ling-hui,XIONG Sheng-ming,SHEN Lin,et al.Experiment of film thickness uniformity by ion beam sputtering deposition of optical thin films[J].Optoelectronic Engineering,2004,31(s1):67-69.李凌辉,熊胜明,申林,等.离子束溅射淀积光学薄膜的膜厚均匀性实验[J].光电工程,2004,31(s1):67-69.
[14] ORTIZ T,CONDE C,KHAN T M,et al.Thickness uniformity and optical/structural evaluation of RF sputtered ZnO thin films for solar cell and other device applications[J].Applied Physics A,2017,123(4):280-286.
[15] DHAWAN R,RAI S,LODHA G S.Effect of ion beam energy on density,roughness&uniformity of Co film deposited using ion beam sputteringsystem[C].American Institute of Physics,2012:691-692.