面阵CCD探测的全自动椭圆偏振光谱系统研究

THE STUDY OF A AUTO ELLIPSOMETER SYSTEM BY USING A TWO-DIMENSIONAL CCD ARRAY DETECTOR

给出了一种椭圆偏振光谱的快速测量方法 ,并使得实验系统的结构更为紧凑和小型化 ,减轻了重量 .研究中采用了由面阵型CCD探测器和平面多光栅组成的光谱仪 ,无需光栅扫描 ,就能够在很短时间内对光谱进行快速准确的数字凝视式成像 ,光谱分辨精度优于 1.0nm ,显著提高了系统工作的可靠性和效率 .系统采取了将CCD光谱仪后置的方式 ,研究并解决了从物理光学原理、器件设计和加工、系统调试和定标、软件编制以及到光谱测量和数据分析等一系列问题 .实验中对典型贵金属Au的光学常数谱进行了测量 ,获得了满意的结果 .

A new type of CCD ellipsometer was designed and constructed to study the optical properties of materials in 5000 similar to 10000 angstrom wavelength range. In the system, the polarizer are driven by a stepping motor that have hollow shafts. The traditional spectroscopic monochromator and photomultiplier were replace by a two-dimensional Si-Based CCD array detector and an integrated grating consisting of three sub-gratings to avoid mechanical transmission, vibration problems and scanning grating entirely. It makes the system simple and reliable, and shorten the time of measurement greatly. The system adopted the technique of arranging CCD Spectrometer at the back. Thus, a series of problems were investigated and solved including the optical principle, instrument design, system calibration, spectra measurement and data analysis. The results from the measured spectra of the complex refractive index for a gold-film sample are presented. It well agrees with the value based on the Drude theory.