Ultrawide Band Gap β-Ga2O3 Nanomechanical Resonators with Spatially Visualized Multimode Motion.
Ultrawide Band Gap β-Ga2O3 Nanomechanical Resonators with Spatially Visualized Multimode Motion.
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DOI：
10.1021/acsami.7b13930
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发表时间：
2017-11
影响因子：
9.5
通讯作者：
Xu-Qian Zheng;Jaesung Lee;S. Rafique;Lu Han;C. Zorman;Hongping Zhao;P. Feng
中科院分区：
文献类型：
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作者：
Xu-Qian Zheng;Jaesung Lee;S. Rafique;Lu Han;C. Zorman;Hongping Zhao;P. Feng
β-氧化镓（β-Ga2O3）是一种新兴的超宽带隙（4.5 eV-4.9 eV）半导体，在未来的电力电子、光电子以及气体和紫外线辐射检测传感器中具有诱人的性能。各种方法制备的β-Ga2O3薄膜正被积极研究用于此类器件。本文报道了利用低压化学气相沉积（LPCVD）法制备β-Ga2O3纳米片制备单晶β-Ga2O3纳米机械谐振器的实验证明。通过对β-Ga2O3圆形鼓面结构的研究，我们在高频和甚高频（HF/VHF）波段展示了高达六模的多模纳米谐振器，并实现了多模运动的空间映射和可视化。这些测量结果表明，杨氏模量EY = 261 GPa，各向异性双轴内置张力为37.5 MPa和107.5 MPa。我们发现，热退火可以显著改善谐振特性，包括频率上升约40%，质量(Q)因子提高约90%。该研究为今后探索和开发机械耦合和可调谐β-Ga2O3电子、光电和物理传感器件奠定了基础。
Beta gallium oxide (β-Ga2O3) is an emerging ultrawide band gap (4.5 eV-4.9 eV) semiconductor with attractive properties for future power electronics, optoelectronics, and sensors for detecting gases and ultraviolet radiation. β-Ga2O3 thin films made by various methods are being actively studied toward such devices. Here, we report on the experimental demonstration of single-crystal β-Ga2O3 nanomechanical resonators using β-Ga2O3 nanoflakes grown via low-pressure chemical vapor deposition (LPCVD). By investigating β-Ga2O3 circular drumhead structures, we demonstrate multimode nanoresonators up to the sixth 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 EY = 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 β-Ga2O3 electronic, optoelectronic, and physical sensing devices.