光栅光谱仪波长校准算法研究

使用正弦曲线拟合进行波长校准时,根据不同的待定系数选择方法,提出三种校准算法.最优算法选定四个待定系数,其中两个线性系数使用最小二乘法计算,而两个非线性系数使用最优化原理求得.线性算法只选定两个线性系数为待定量,而非线性系数为确定值.简化算法仅选定一个线性系数为待定量,其余三个系数为确定值.实测数据表明,线性算法拟合准确度接近最优解,计算复杂度低,是一种最适合于光栅光谱仪波长校准的算法.

Applications of the Wavelet Transform to Characterize the Oxide Layer,Interlayer and Thickness Fluctuation in Multilayer Structures

Wavelet transform is used to analyze the grazing incidence X ray reflectivity curve of nanometer multilayer structures.For the structures including oxide layers,interlayers or thickness fluctuations,which are difficult to determine,wavelet transform can be used to get structure parameters from the peak positions and peak intensities of auto correlation functions.Using these results as initial model of further curve fitting,the multilayer structures can be characterized accurately.The oxide layer of vanadium monolayer is determined to be about 3nm,the interfacial roughness of Mo/Si multilayer structures is about 0.42nm,and the results show that the thickness fluctuations of layers close to surface and substrate are over 5%.