论文部分内容阅读
研究了一种采用横向塞曼激光器并且没有任何运动部件的外差干涉椭偏测量系统。由非理想的激光源、偏振分光镜等器件所产生的非线性误差,是影响纳米测量精度的主要因素。采用琼斯矢量法,分析并建立了光学系统寄生虚反射所引入的误差模型,讨论了虚反射对误差漂移的影响。在不考虑其它误差因素的前提下,同一光路内部产生的同频率虚反射波对测量结果没有影响;而不同频率的参考光束与测量光束之间的交叉虚反射所产生的膜厚测量误差为亚纳米量级。讨论了消除和抑制虚反射误差的方法。
A heterodyne interferometry ellipsometry system using a transverse Zeeman laser with no moving parts was studied. Non-linear errors caused by non-ideal laser sources, polarization beam splitters and other devices are the main factors affecting the measurement accuracy of nanometers. The error model introduced by parasitic false reflection of optical system is analyzed and established by Jones vector method, and the influence of false reflection on error drift is discussed. Without accounting for other error factors, the same frequency generated by the same road within the same frequency reflections on the measurement results have no effect; and different frequency of the reference beam and measured beam cross-reflection between the film thickness error is y Nano-scale. The methods to eliminate and suppress the false reflection error are discussed.