Novel Method of Measuring the Thickness of Nanoscale Films Using Energy Dispersive X‐Ray Spectroscopy Line Scan Profiles

The cross-sectional transmission electron microscopy (TEM) imaging method is widely used to determine the nanoscale thickness of thin films. However, thin films to be analyzed within TEM samples often have a curved or distorted shape, or poor alignment with the electron beam direction, which can easily overestimate the thickness due to TEM projection artifacts. This study develops a novel method to measure the thickness of thin films using a TEM energy-dispersive X-ray spectroscopy (EDS) line scan. This method is based on the constant integration of the quantitative line scan profile regardless of geometric configuration, making it possible to overcome the projection problem. The proposed method is experimentally validated with a Si/Ti/Si stacked sample. The EDS line scan is performed at various tilt angles at the same location, and it is confirmed that the integration of each quantification profile has the same value, thus providing a consistent thickness value. This method is effective in measuring the thickness of the thin film more accurately and reliably regardless of the inclination angle of the thin film.