Yu Xi, Zhu Lei, Li Xin, Zhao Jia, Wu Tingjun, Yu Wenjie, Li Weimin
School of Microelectronics, Shanghai University, Shanghai 201899, China.
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Materials (Basel). 2023 Feb 21;16(5):1778. doi: 10.3390/ma16051778.
The piezoelectric and elastic properties are critical for the performance of AlN-based 5G RF filters. The improvement of the piezoelectric response in AlN is often accompanied by lattice softening, which compromises the elastic modulus and sound velocities. Optimizing both the piezoelectric and elastic properties simultaneously is both challenging and practically desirable. In this work, 117 XYAlN compounds were studied with the high-throughput first-principles calculation. BErAlN, MgTiAlN, and BeCeAlN were found to have both high (>249.592 GPa) and high (>1.869 C/m). The COMSOL Multiphysics simulation showed that most of the quality factor () values and the effective coupling coefficient () of the resonators made with these three materials were higher than those with ScAlN with the exception of the of BeCeAlN, which was lower due to the higher permittivity. This result demonstrates that double-element doping of AlN is an effective strategy to enhance the piezoelectric strain constant without softening the lattice. A large can be achieved with doping elements having d-/f- electrons and large internal atomic coordinate changes of . The doping elements-nitrogen bond with a smaller electronegativity difference () leads to a larger elastic constant .
压电和弹性性能对于基于AlN的5G射频滤波器的性能至关重要。AlN中压电响应的改善通常伴随着晶格软化，这会损害弹性模量和声速。同时优化压电和弹性性能既具有挑战性又在实际中很有必要。在这项工作中，通过高通量第一性原理计算研究了117种XYAlN化合物。发现BErAlN、MgTiAlN和BeCeAlN具有高的弹性模量（>249.592 GPa）和高的压电应变常数（>1.869 C/m）。COMSOL多物理场模拟表明，用这三种材料制成的谐振器的品质因数（）值和有效耦合系数（）大多高于用ScAlN制成的谐振器，BeCeAlN的除外，由于其介电常数较高，其较低。该结果表明，AlN的双元素掺杂是增强压电应变常数而不使晶格软化的有效策略。通过具有d-/f-电子且内部原子坐标变化大的掺杂元素可以实现大的压电应变常数。掺杂元素与氮之间的电负性差（）较小会导致弹性常数较大。
