New Strategy to Improve the Accuracy of Quantitative Analysis of Energy Dispersive Spectroscopy

Abstract

Abstract Elemental quantification of several single crystalline TEM samples of intermediate thickness range that cannot be quantified by the thin-film approximation method and the ZAF correction were investigated using wedge-shaped samples of known thickness fabricated by the FIB technique. "Thickness factor (TF)" and "Thickness correction coefficient (TC)" were proposed as error correction items of "thin-film approximation method" to minimize the quantitative error that occurs when quantifying samples of intermediate thickness with TEM-EDS. As the result of TF correction, the quantification error in an Al2O3 TEM sample by TEM-EDS was reduced from about 52.15% to less than 3.28 (± 2.57) % by the correction of only one time. The self-absorption corrected line profiles and self-absorption corrected elemental mapping images in TEM samples of intermediate thickness range were also obtained by TF correction. As an example of application by TF correction, we proposed a novel method measuring thin-film thickness in normal TEM without the EELS system. The TF correction technique is a unique method to overcome the limitation of EDS quantification in the intermediate thickness range. This technique can effectively quantify characteristic X-ray lines less than 1,000 eV in the sample having intermediate thickness ranges using the conventional TEM-EDS system. It is expected to contribute significantly to understanding various characteristics or material nature related to material composition and sample thickness in nanomaterials because it provides more precise quantitative analysis information than current commercial EDS systems.