用于线宽测量的偏振干涉共焦显微测量方法  

A System for Measurement of Line Width by Combining Polarization Interferometry with Confocal Microscopy

作　　者：柳忠尧[1] 闫聚群[1] 张蕊[1] 林德教[1] 殷纯永[1] 叶孝佑[2] 许婕[2] 

机构地区：[1]清华大学精密仪器与机械学系精密测量技术与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：《计量学报》2005年第2期115-119,共5页Acta Metrologica Sinica

基　　金：国家自然科学基金(50027002)

摘　　要：提出一种融合共焦显微技术和偏振干涉技术的偏振干涉共焦显微测量方法。利用共焦技术进行准确的焦点定位,以获得最佳的测量光斑;同时,利用照射到台阶边缘的不同偏振方向(平行和垂直于台阶边缘)的线偏振光反射后产生的相位变化不同这一特性,进行边缘定位。相位变化是利用外差干涉测相的方法得到的。这一系统完全符合共光路原则,有很强的抗干扰能力。利用该系统对标准线宽样板进行了测量,测量结果与中国计量科学研究院用原子力显微镜测量的结果,以及厂商提供的可溯源到美国NIST光学线宽标准的测量值都符合的很好;还对同一刻线进行了5次重复性测量,其极限偏差为20nm。A novel system for measuring the step height and line width of mask plates is proposed, which combines polarization interferometry with confocal microscopy. The orthogonally linearly-polarized light from a Transverse Zeeman Laser (TZL) is used as the light source. By locating the focus precisely, the most measurable facular is obtained. Then, the phase drift of the TE-polarized light and the TM-polarized light (their orientation of vibration of electrical field is parallel or perpendicular to the edge) are measured by the heterodyne interferometry method after they were reflected by the edge. So the edge is localized when the phase drift is analyzed by computer. The system has strong ability of anti-environmental disturbance for it meets with the rule of common path. The result of the measurement for an international standard line-width specimen with the NIM's Atomic Force Microscope (AFM) is quite agreed with that of our system. The results also show the system has good repeatability with maximum deviation of 20 nm when the same line is measured for 5 times.

关 键 词：计量学 偏振干涉 边缘探测 线宽 共光路设计 共焦显微术 

分 类 号：TB92[一般工业技术—计量学]