A method of using Si L-edge for O/Si and N/Si quantitative ratio analysis by electron energy loss spectroscopy (EELS)

In EELS core loss excitation, inverse jump ratio is defined as a ratio between intensity of a pre-core-loss-edge and a signal of the core loss excitation after background subtraction. A linear relationship between inverse jump ratio of Si L-edge and O/Si and N/Si intensity ratio is found for electron energy loss spectroscopy (EELS) analysis. This relationship is used to analyze O/Si and N/Si atomic ratio to quantify the elemental distribution in SiON films and the result is compared with XPS analysis on the same SiON films. The method is applied to blanket wafer elemental analysis and can be used for flash memory structure (3D NAND) to obtain atomic ratios of N/Si and O/ Si for tunnel oxide at sub-nanometer scale.

Automated summary

In this study, a linear relationship was found between the inverse jump ratio of Si L edge and the O/Si and N/Si intensity ratio, which is used for EELS analysis. This method is applied to analyze the elemental distribution in SiON films and compared with XPS analysis. It can also be utilized for flash memory structure (3D NAND) to obtain atomic ratios of N/Si and O/Si for tunnel oxide at a sub-nanometer scale.