Quantitative high resolution transmission electron microscopy

Abstract

High resolution transmission electron microscopy (HRTEM) has been extensively used as a structure characterization technique in materials and biological science. In the past, qualitative use of HRTEM has been primarily employed.

This thesis explores the use of HRTEM as a quantitative tool, which should have great impact on the atomic level analysis of numerous materials science problems, such as interface interdiffusion in heterostructures. In order to implement quantitative HRTEM, a clear understanding of the electron imaging and scattering theories is necessary. Moreover, several issues which directly relate to the success of high resolution electron microscopy work, such as the characteristics of a microscope and the specimen preparation, will be addressed. As an example, the application of HRTEM to a materials science problem will be demonstrated. Through this study, limitations of the qualitative HRTEM will be manifested and the quantitative HRTEM based on a non-linear least-square method will follow. This quantitative method allows determination of the imaging parameters and hence, the quantitative structure and chemical analysis can then be carried on. However, the inadequacy of the existing theory in quantitative matching of experimental images will be demonstrated, and further theoretical developments are required to implement the method.