Development of an element distribution quantification method for electron energy loss spectra

Abstract

Quantitatively grasping state change such as element distribution change due to manufacturing process is important in developing high performance devices. Electron energy loss spectroscopy (EELS) is known as a method for analyzing the state of a measurement sample. Multivariate Curve Resolution Alternative Least Squares (MCRALS) has been proposed as a method to obtain element concentration distribution from information measured by EELS. However, in MCRALS, when there is similarity between spectra of pure components contained in the sample, the estimation result becomes unstable. In this study, attention was paid to the fact that the concentration distribution must be smooth, and attempts were made to solve the instability by introducing a smoothing process on the concentration distribution in the process of calculating the concentration distribution of elements using MCRALS. Effectiveness was confirmed by applying the proposed method to the EELS data before and after annealing of the Ti / Ti - O sample layered on the Si substrate and estimating the state of oxygen diffusion.