Young's Modulus and Corresponding Orientation in \beta-Ga2O3 Thin Films Resolved by Nanomechanical Resonators

TL;DR

This study non-destructively measures the Young's modulus of beta-Ga2O3 thin films using nanomechanical resonators, providing key mechanical properties and orientation dependence crucial for nanoelectromechanical applications.

Contribution

It introduces a method to measure Young's modulus of beta-Ga2O3 nanostructures via resonance frequencies, aligning experimental results with theoretical predictions.

Findings

Young's modulus in (100) plane: 261.4 GPa

Young's modulus in [010] direction: 245.8 GPa

Results agree with first-principle calculations

Abstract

We report on the non-destructive measurement of Young's modulus of thin-film single crystal beta gallium oxide (beta-Ga2O3) out of its nanoscale mechanical structures by measuring their fundamental mode resonance frequencies. From the measurements, we extract Young's modulus in (100) plane, EY,(100) = 261.4+/-20.6 GPa, for beta-Ga2O3 nanoflakes synthesized by low-pressure chemical vapor deposition (LPCVD), and Young's modulus in [010] direction, EY,[010] = 245.8+/-9.2 GPa, for beta-Ga2O3 nanobelts mechanically cleaved from bulk beta-Ga2O3 crystal grown by edge-defined film-fed growth (EFG) method. The Young's moduli extracted directly on nanomechanical resonant device platforms are comparable to theoretical values from first-principle calculations and experimentally extracted values from bulk crystal. This study yields important quantitative nanomechanical properties of beta-Ga2O3 crystals, and helps pave the way for further engineering of beta-Ga2O3 micro/nanoelectromechanical systems (M/NEMS) and transducers.