一种可溯源的光谱椭偏仪标定方法  

A traceable calibration method for spectroscopic ellipsometry

作　　者：张继涛[1] 李岩[1] 罗志勇[2] 

机构地区：[1]清华大学精密仪器与机械学系、精密测试技术及仪器国家重点实验室,北京100084 [2]中国计量科学研究院,北京100013

出　　处：《物理学报》2010年第1期186-191,共6页Acta Physica Sinica

基　　金：国家科技支撑计划(批准号:2006BAF06B06)资助的课题~~

摘　　要：提出了一种用X射线反射术标定光谱椭偏仪的方法.作为一种间接测量方法,光谱椭偏术测得的薄膜厚度依赖于其光学常数,不具有可溯源性.在掠入射条件下,X射线反射术能测得薄膜的物理厚度,测量结果具有亚纳米量级的精密度且与薄膜光学常数无关.在单晶硅基底上制备了厚度分别为2nm,18nm,34nm,61nm及170nm的SiO2薄膜标样,并用强制过零点的直线拟合了两种方法的标样测量结果,拟合直线的斜率为1.013±0.013,表明该方法可在薄膜厚度测量中标定光谱椭偏仪.A method for calibrating the spectroscopic ellipsometry by X-ray reflectivity is presented. As an indirect method, spectroscopic ellipsometry does not have the traceability because the measured film thickness is dependent on its optical constant. In contrast, at the grazing angle, the X-ray reflectivity can be used to measure the absolute thickness of thin film with sub- nanometer precision, and is independent of the optical constant. Five SiO2 films were deposited on the substrate of single crystal silicon with the thickness of 2 nm, 18 nm,34 nm,61 nm, and 170 nm, respectively. The results of spectroscopic ellipsometry and X-ray reflectivity were well fitted by a liner equation with slope this calibration method is valid for spectroscopic ellipsometry in of 1.013 ± 0.013 and its intercept was set to zero,which means the determination of the thickness of thin films.

关 键 词：光谱椭偏术 X射线反射术 膜厚 标定 

分 类 号：O484.5[理学—固体物理] TN244[理学—物理]