基片材料与沉积参数对薄膜应力的影响  

Effects of Substrate Materials and Deposition Parameters on Film Stress

作　　者：李玉琼[1] 喻志农[1] 王华清[1] 卢维强[1] 薛唯[1] 丁瞾[1] 

机构地区：[1]北京理工大学光电学院薄膜与显示技术实验室,北京100081

出　　处：《光学学报》2010年第2期602-608,共7页Acta Optica Sinica

基　　金：国家部委预研项目(51302060203)资助课题

摘　　要：采用哈特曼-夏克传感器的薄膜应力在线测量仪测量了利用离子辅助电子束蒸发的Si O2,Ti O2,Ta2O5,Al2O3与ITO薄膜在不同厚度时的应力值,并深入研究了基片材料与沉积参数对Si O2,Ti O2薄膜应力的影响。研究结果表明,在成膜的初始阶段,薄膜应力与薄膜厚度基本上呈线性函数,当达到一定厚度时薄膜应力基本趋于一个定值;薄膜与基片的热失配将引起薄膜热应力,通过选择合适的基片材料可以使其降低;对Ti O2薄膜而言,当基片温度低于150℃时,热应力起主要作用,当基片温度高于150℃时,薄膜致密引起的压应力占主导地位,但Si O2薄膜其热应力始终占主导地位;当真空室压强低于1.7×10-2Pa时,Si O2薄膜的张应力主要是由离子辅助溅射效应而引起,当真空室压强高于1.7×10-2Pa时,Si O2薄膜的张应力随着压强的增大而增大,但折射率减小。An on-line thin film stress measuring system based on Hartmann-Shack sensor technique is introduced to measure the film stress of SiO2,TiO2,Ta2O5,Al2O3 and ITO films at different thickness which are prepared by ion assisted deposition,and the effects of substrate materials and preparation parameters on the stresses of SiO2 and TiO2 are investigated in details. The results show that the film stress as a function of the film thickness is linear in the initial stage of coating,and the film stress tends to be a stable value when the film thickness reaches a certain value. The thermal stress which resulted from the different coefficients of thermal between substrates and thin films can be diminished by choosing suitable substrates. In terms of TiO2 films,the thermal stress plays a major role when the substrate temperature is below 150 ℃,but the compressive stress which resulted from the dense structure of films is dominant while the substrate temperature is above 150 ℃. However,the thermal stress in SiO2 films is always dominant at different deposition temperatures. The tensile stress in SiO2 films is mainly caused by the effects of ion assisted sputtering when the chamber pressure is below 1.7×10^-2 Pa,and the tensile stress in SiO2 films increases with the vacuum chamber′s pressure increasing when it is above 1.7×10^-2 Pa,but the refractive index decreases.

关 键 词：薄膜光学 薄膜应力 哈特曼-夏克传感器 基片材料 沉积参数 离子辅助沉积 

分 类 号：TB43[一般工业技术]