This paper presents an Aluminum Nitride (AlN) Lamb-wave resonator with high series-resonance quality factors (Q_s) and good spectral purity. The influence of the interdigitated (IDT) electrode width and electrical boundary condition was theoretically analyzed to improve effective electro-mechanical coupling coefficient (k²_eff) and spectral purity. According to the structural characteristic of the designed resonators, an advanced micro-manufacturing process was designed. A thermal oxide layer was employed to avoid the etching of inactive regions, which contributes to achieving the high Q_s and high-yield fabrication. The measured results show the IDT-ground resonators with 12 μm and 6 μm electrode periods exhibit Q_s values as high as 4457.1 and 2625.1, and k²_eff of 0.61% and 0.33%, respectively. The IDT-IDT resonators have higher k²_eff, but their Q_s values are severely attenuated. Through observing their section morphologies, the measured shear angles of the bottom IDT electrodes with 12 μm and 6 μm periods are 54.95° and 65.7° respectively, and the surface AlN film has tiny cracks, which induces the performance deterioration of the IDT-IDT resonators. Moreover, the influence of the IDT material on the resonator’s performance was also analyzed.

本文介绍了一种具有高串联谐振品质因数 ( Q _s ) 和良好光谱纯度的氮化铝 (AlN) 兰姆波谐振器。理论上分析了叉指（IDT）电极宽度和电边界条件的影响，以提高有效机电耦合系数（k ² _eff）和光谱纯度。根据所设计谐振器的结构特点，设计了一种先进的微制造工艺。采用热氧化层来避免蚀刻非活性区域，这有助于实现高Q _s和高产制造。测量结果表明，电极周期为 12 μm 和 6 μm 的 IDT 接地谐振器的Q _s值分别高达 4457.1 和 2625.1，k ² _eff分别为 0.61% 和 0.33%。IDT-IDT 谐振器具有更高的k ² _eff，但它们的Q _s值严重衰减。通过观察它们的截面形貌，12 μm和6 μm周期的底部IDT电极的实测剪切角分别为54.95°和65.7°，表面AlN薄膜有微小的裂纹，导致IDT-IDT谐振器的性能劣化. 此外，还分析了IDT材料对谐振器性能的影响。