光学仪器, 2020, 42 (3): 71, 网络出版: 2020-08-13
真空紫外–极紫外反射率计控制与数据采集系统 下载: 675次
Control and data acquisition system for VUV-EUV reflectometer
摘要
针对自行研制的真空紫外-极紫外(VUV–EUV)波段反射率计运行需要,基于LabVIEW软件构建了该反射率计控制和数据采集系统。详细介绍该系统的组成和主要硬件单元模块的控制流程与方法,并给出准直调试程序和反射率数据采集程序的架构、用户界面和数据采集方法。提出的新数据采集算法有效提高了弱信号条件下反射率测量的可靠性。利用该控制与数据采集系统,对Si基板开展了准直校准与反射率测量实验。结果表明,在7.5°~87.5°范围内直通光电流信号为20 pA时仍能获得可靠的反射率,且基于入射光监测方法的反射率测量实验结果与理论计算相符更好。除在布儒斯特角附近信号电流小于本底电流0.7 pA时,反射率重复测量误差优于1.6%。
Abstract
Aiming at the operation needs of the self-developed vacuum ultraviolet-extreme ultraviolet (VUV-EUV) reflectometer, this reflectometer control and data acquisition system was constructed based on LabVIEW software. In this paper, the basic structure and function of the device are firstly introduced. In particular, the control flow and methods of the main hardware unit modules of the system are introduced in detail, including the framework, the program interface and the way for collecting data. This study proposes a new data acquisition algorithm that effectively improves the reliability of reflectance measurements, especially for measuring weak signals. Using this control and data acquisition system, a collimation calibration and reflectance measurement experiment was performed on a Si substrate sample. The results show that a reliable reflectance can still be obtained when the shoot-through photocurrent signal was as low as 20 pA in the range of 7.5°-87.5°, and the reflectance measurement results based on the incident light monitoring method are in good agreement with the theoretical calculations. When the signal current acquired at the angle around the Brewster angle is more than the background current by 0.7 pA, the repeatable measurement error of the reflectance is generally better than 1.6%.
谢春, 姚倩霞, 余越, 李文斌. 真空紫外–极紫外反射率计控制与数据采集系统[J]. 光学仪器, 2020, 42(3): 71. Chun XIE, Qianxia YAO, Yue YU, Wenbin LI. Control and data acquisition system for VUV-EUV reflectometer[J]. Optical Instruments, 2020, 42(3): 71.