Fast nanothermometry based on direct electron detection of electron backscattering diffraction patterns

TL;DR

This paper introduces a rapid, non-contact nanothermometry technique using electron backscattering diffraction patterns in SEMs, achieving high spatial resolution and sensitivity for thermal mapping at the nanoscale.

Contribution

The work develops a novel Fourier analysis method to detect temperature-induced changes in EBSD patterns, enabling high-sensitivity, real-time thermal measurements in SEMs.

Findings

Simulated temperature sensitivity of ~0.15% per K.

Experimental sensitivity of 0.14% per K on silicon.

Achieved 13-K temperature uncertainty with 10-second acquisition.

Abstract

Accurate temperature measurement at the nanoscale is crucial for thermal management in next-generation microelectronic devices. Existing optical and scanning-probe thermometry techniques face limitations in spatial resolution, accuracy, or invasiveness. In this work, we demonstrate a fast and non-contact nanothermometry method based on temperature-induced changes in electron backscattering diffraction (EBSD) patterns captured by a high-performance direct electron detector within a scanning electron microscope (SEM). Using dynamical electron simulations, we establish the theoretical temperature sensitivity limits for several semiconductors (Si, Ge, GaAs, and GaN), showing that thermal diffuse scattering (TDS) leads to a measurable smearing of Kikuchi bands in the EBSD patterns. We develop a Fourier analysis method that captures these subtle changes across the full diffraction pattern, achieving a simulated temperature sensitivity of approximately 0.15\% per K. Experimental results on silicon confirm a sensitivity of 0.14\% per K and achieve a 13-K temperature uncertainty with a 10-second acquisition time, and enable spatial temperature mapping under thermal gradients. Our approach offers a pathway toward practical and high-resolution thermal mapping directly in SEMs, expanding the toolbox for device-level thermal diagnostics.