TiO_2和SiO_2薄膜应力在线测量与研究

Growth and On-Line Stress Evaluation of TiO_2 and SiO_2 Films

研究了离子能量在薄膜制备过程中对TiO2和SiO2薄膜应力的影响。用电子束蒸发的方法制备TiO2和SiO2薄膜,使用实验室自行设计制作的基于哈特曼传感器的薄膜应力仪在线监测TiO2和SiO2薄膜应力随膜厚的变化。结果表明,离子辅助沉积的TiO2薄膜张应力值要比传统工艺低40 MPa,并且随着离子能量的增加,薄膜逐渐由张应力变为压应力,薄膜的最大折射率为2.56;而离子辅助的溅射效应在制备SiO2薄膜时比较明显,传统工艺制备的SiO2薄膜表现为压应力,而用离子辅助的方法制备的SiO2薄膜表现为张应力,并且随着离子能量的增加,薄膜变得疏松,折射率逐渐降低。

Here we addressed the on-line stress evaluation of the TiO2 and SiO2 films,grown by ion beam assisted deposition（IBAD） and electron beam evaporation on glass substrates,respectively.The impacts of ion energy and film thickness on variations in the stress distribution during the film growth were characterized online with a lab-built stress measurement setup,based on Hartmann sensor.The results show that the ion sputtering significantly affects the stress and distributions of both the TiO2 and SiO2 films.For example,the tensile stress of the IBAD TiO2 film is 40 MPa lower than that of the electron-beam evaporated films.Moreover,as the ion energy increased,the tensile stress gradually changed into the compressive stress;and its refractive index increased,with a peak of 2.56.In case of SiO2 film growth,the ion beam assistance affects more strongly the stress and microstructures.The ion sputtering results in a dominance of the tensile stress,whereas compressive stress prevailed in electron-beam evaporated SiO2 films.Besides,an increasing ion-energy roughens its surface,and reduces its refractive index.