Abstract High-frequency and wideband surface acoustic wave (SAW) devices have become an important topic in 5G communication systems and beyond. For this purpose, piezoelectric ScAlN thin films deposited on high SAW velocity diamond are studied in SAW resonators on the polycrystalline diamond (PCD) and hetero-epitaxial diamond (HED) substrates. A very strong c-axis orientation of ScAlN on HED was confirmed. Interdigital transducers of 0.8 μm and 0.5 μm were fabricated to realize 2.2 to 3.5 GHz high-frequency resonators. High Q values were obtained for the 2.3–2.5 GHz device on both PCD and HED. Additionally, a high electro-mechanical coupling coefficient (K2) of 5.40–5.52% and high SAW velocities of 7400–7766 m/s were obtained in the 2.3–2.5 GHz devices. In comparison to the simulated coupling coefficient results of a previous report, ScAlN/diamond might have higher K2 for the Sezawa wave.

中文翻译：

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ScAlN/异质外延金刚石高频声表面波谐振器

摘要 高频和宽带表面声波 (SAW) 器件已成为 5G 通信系统及以后的重要课题。为此，在多晶金刚石 (PCD) 和异质外延金刚石 (HED) 基板上的 SAW 谐振器中研究了沉积在高 SA​​W 速度金刚石上的压电 ScAlN 薄膜。确认了 HED 上 ScAlN 的非常强的 c 轴取向。制造了 0.8 μm 和 0.5 μm 的叉指换能器，以实现 2.2 至 3.5 GHz 的高频谐振器。PCD 和 HED 上的 2.3–2.5 GHz 器件都获得了高 Q 值。此外，在 2.3-2.5 GHz 器件中获得了 5.40-5.52% 的高机电耦合系数 (K2) 和 7400-7766 m/s 的高 SAW 速度。与之前报告的模拟耦合系数结果相比，