掺钪AlN材料特性及HBAR器件性能研究

该文基于掺钪AlN薄膜制备了高次谐波体声波谐振器(HBAR),研究了钪(Sc)掺杂浓度对AlN压电薄膜材料特性及器件性能的影响。研究表明,当掺入Sc的摩尔分数从0增加到25%时,压电应力系数e₃₃增加、刚度 下降,导致Al₁-_xSc_xN压电薄膜的机电耦合系数 从5.6%提升至15.8%,从而使HBAR器件的有效机电耦合系数 提升了3倍。同时,当Sc掺杂摩尔分数达25%时,Al₁-_xSc_xN(x为Sc掺杂摩尔分数)压电薄膜的声速下降13%,声学损耗提高,导致HBAR器件的谐振频率和品质因数降低。

Study on the Scandium-Doped AlN Films and HBAR Devices

In this paper, the high-overtone bulk acoustic resonators (HBAR) were fabricated based on the scandium-doped AlN thin films, and the effect of scandium(Sc) doping concentration on the material properties of AlN piezoelectric thin films as well as the performance of devices were investigated. The results showed that, as the Sc mole fraction increased from 0 to 25%, the piezoelectric stress coefficient e₃₃ increased and the stiffness constant decreased, resulting in an increase of the electromechanical coupling coefficient of Al₁-_xSc_xN piezoelectric film from 5.6% to 15.8%, thereby increasing the effective electromechanical coupling coefficient of HBAR device by a factor of three. At the same time, when the Sc mole fraction was up to 25%, the sound velocity of the Al_1-xSc_xN film piezoelectric film was reduced by 13%, and the acoustic loss was increased, resulting in a decrease of the resonant frequency and quality factor Q of the HBAR device.