Measurement of electron beam induced sample heating in SEM experiments

TL;DR

This paper investigates how electron beams in SEM experiments cause localized heating in samples, measuring temperature increases with a MEMS device and simulations, highlighting the influence of experimental parameters on heating effects.

Contribution

It introduces a direct measurement method for electron-beam-induced heating in SEM samples using a MEMS device, validated by simulations, and analyzes parameter effects on temperature rise.

Findings

Sample temperature can increase by up to 70°C during EBSD.

Beam current has the most significant impact on heating.

Higher acceleration voltages also increase sample temperature.

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 1$\mu$s to 1ms) and sample tilt (0{\deg} to 70{\deg}). The findings reveal that local sample temperatures can increase by up to 70 {\deg}C during EBSD experiments, primarily affected by the choice in beam current and acceleration voltage, with beam current having the most significant impact.