Department of Physics, University of Texas at Austin, Austin, TX, 78712, USA.
Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX, 78712, USA.
Nat Commun. 2023 Mar 2;14(1):1188. doi: 10.1038/s41467-023-36936-9.
Implementing microelectromechanical system (MEMS) resonators calls for detailed microscopic understanding of the devices, such as energy dissipation channels, spurious modes, and imperfections from microfabrication. Here, we report the nanoscale imaging of a freestanding super-high-frequency (3 - 30 GHz) lateral overtone bulk acoustic resonator with unprecedented spatial resolution and displacement sensitivity. Using transmission-mode microwave impedance microscopy, we have visualized mode profiles of individual overtones and analyzed higher-order transverse spurious modes and anchor loss. The integrated TMIM signals are in good agreement with the stored mechanical energy in the resonator. Quantitative analysis with finite-element modeling shows that the noise floor is equivalent to an in-plane displacement of 10 fm/√Hz at room temperatures, which can be further improved under cryogenic environments. Our work contributes to the design and characterization of MEMS resonators with better performance for telecommunication, sensing, and quantum information science applications.
实现微机电系统 (MEMS) 谐振器需要对器件进行详细的微观理解，例如能量耗散通道、杂模和微加工的不完美。在这里，我们报告了具有前所未有的空间分辨率和位移灵敏度的自由-standing 超高频率（3-30GHz）横向泛音体声波谐振器的纳米级成像。使用传输模式微波阻抗显微镜，我们已经可视化了单个泛音的模式轮廓，并分析了高阶横向杂模和锚固损耗。集成的 TMIM 信号与谐振器中存储的机械能很好地吻合。通过有限元建模的定量分析表明，在室温下，噪声基底相当于 10fm/√Hz 的面内位移，在低温环境下可以进一步提高。我们的工作为 MEMS 谐振器的设计和特性分析提供了帮助，有助于实现用于电信、传感和量子信息科学应用的性能更好的谐振器。
