This work presents the development of a novel process flow for the fabrication of Lithium niobate Lamb wave resonator that allows full control of the shape and size of the released area (undercut) necessary for stabilizing quality factor. We then investigate the influence of the inactive regions of the resonator (i.e. undercut, anchor, bus and gap) on $Q$ ; and determine the optimum dimensions for those regions in order to limit the flow of energy escaping from the resonator’s body resulting in overall improvement in $Q$ . We report devices with electromechanical coupling ( $k_{t}^{2}$ ) of 41% and quality factor ( $Q$ ) of 1900 at around 290 MHz resulting in the highest-ever achieved Figure-of-Merit (FoM) of 780 for SH0 mode resonators in X-cut LN. [2020-0363]

中文翻译：

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优化铌酸锂剪切模式谐振器的非活性区域以提高品质因数

这项工作提出了一种用于制造铌酸锂兰姆波谐振器的新工艺流程的开发，该流程允许完全控制稳定品质因数所需的释放区域（底切）的形状和大小。然后我们研究谐振器的非活动区域（即底切、锚定、总线和间隙）对 $Q$ ; 并确定这些区域的最佳尺寸，以限制从谐振器主体逸出的能量流，从而整体改善 $Q$ . 我们报告了具有机电耦合的设备（ $k_{t}^{2}$ ) 的 41% 和品质因数 ( $Q$ ) 在 290 MHz 附近达到 1900 的最高品质因数 (FoM)，对于 X-cut LN 中的 SH0 模式谐振器，达到了 780 的最高品质因数 (FoM)。[2020-0363]