Measurement of electron beam induced sample heating in SEM experiments

  • 1National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark (DTU), Kgs Lyngby, Denmark.
  • 2National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark (DTU), Kgs Lyngby, Denmark. Electronic address: absf@dtu.dk.
  • 3National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark (DTU), Kgs Lyngby, Denmark. Electronic address: jojin@dtu.dk.

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Abstract

Scanning Electron Microscopy (SEM) experiments provide detailed insights into material microstructures, enabling high-resolution imaging as well as crystallographic analysis through advanced techniques like Electron Backscatter Diffraction (EBSD). However, the interaction of the high-energy electron beam with the material can lead to localized heating, which may significantly impact specimen integrity, especially in applications requiring prolonged beam exposure, for instance when mapping the crystal structure using EBSD. This study examines electron-beam-induced heating effects on a model metal sample (iron), directly measuring the locally deposited electron beam energy with a MEMS-based heating device and validating these measurements through simulations, including Monte Carlo and Finite Element methods. The analysis focuses on the effects of various experimental parameters such as acceleration voltage (from 5 to 30 kV), beam current (from 0.17 nA to 22 nA), dwell time (from 1µs to 1 ms) and sample tilt (0° to 70°). The findings reveal that local sample temperatures can increase by up to 70 °C during EBSD experiments, primarily affected by the choice in beam current and acceleration voltage, with beam current having the most significant impact.

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