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arXiv · 1807.00355

Ultrawide Band Gap \beta-Ga2O3 Nanomechanical Resonators with Spatially Visualized Multimode Motion

Xu-Qian Zheng·Jaesung Lee·Subrina Rafique·Lu Han·Christian A. Zorman·Hongping Zhao·Philip X. -L. Feng
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Abstract

Beta gallium oxide (\beta-Ga2O3) is an emerging ultrawide band gap (4.5 - 4.9 eV) semiconductor with attractive properties for future power electronics, optoelectronics, and sensors for detecting gases and ultraviolet radiation. \beta-Ga2O3 thin films made by various methods are being actively studied toward such devices. Here, we report on the experimental demonstration of single-crystal \beta-Ga2O3 nanomechanical resonators using \beta-Ga2O3 nanoflakes grown via low-pressure chemical vapor deposition (LPCVD). By investigating \beta-Ga2O3 circular drumhead structures, we demonstrate multimode nanoresonators up to the 6th mode in high and very high frequency (HF / VHF) bands, and also realize spatial mapping and visualization of the multimode motion. These measurements reveal a Young's modulus of E_Y = 261 GPa and anisotropic biaxial built-in tension of 37.5 MPa and 107.5 MPa. We find that thermal annealing can considerably improve the resonance characteristics, including ~40% upshift in frequency and ~90% enhancement in quality (Q) factor. This study lays a foundation for future exploration and development of mechanically coupled and tunable \beta-Ga2O3 electronic, optoelectronic, and physical sensing devices.

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BibTeXRIS

Xu-Qian Zheng, Jaesung Lee, Subrina Rafique, Lu Han, Christian A. Zorman, Hongping Zhao, Philip X. -L. Feng. 2018-07-01. Ultrawide Band Gap \beta-Ga2O3 Nanomechanical Resonators with Spatially Visualized Multimode Motion. https://doi.org/10.1021/acsami.7b13930

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