A Film Bulk Acoustic Resonator Based on Ferroelectric Aluminum Scandium Nitride Films
A Film Bulk Acoustic Resonator Based on Ferroelectric Aluminum Scandium Nitride Films
复制标题
DOI：
10.1109/jmems.2020.3014584
复制
发表时间：
2020-10-01
影响因子：
2.7
通讯作者：
Ansari, Azadeh
中科院分区：
文献类型：
--
作者：
Wang, Jialin;Park, Mingyo;Ansari, Azadeh
基于Sc/(Al+Sc)比约为AlScN的溅射AlScN压电薄膜，首次实现了薄膜体声谐振器(FBARs)的频率调谐和本征极化开关。30%。获得了900 nm厚的Al0.7Sc0.3N溅射薄膜的盒状铁电磁滞行为，显示出与3 mV/cm相似的矫直电场。在3.17 GHz频率下测量了体声波(BAW)谐振器的基波厚度模共振，其机电耦合系数(k(T)(2))为18.1%。研究了两种情况下的FBAR频率响应：(I)在直流电场低于矫顽场时的线性调谐区域，以及(Ii)在高于矫顽场的电场作用下的极化转换区域。在情况(I)中，由于Sc含量较高，获得了215ppm×mum/V的大的线性调谐范围。在(Ii)中，当在Al0.7Sc0.3N厚度上施加350 V单极波形时，FBAR的串联谐振频率被打开和关闭。这是第一次演示具有大调谐范围的本质上可切换的AlN基FBAR；并且迄今为止报道的AlN基FBAR的创纪录的高k(T)(2)。此外，本工作还为实现工作在超高频(SHF)的可调谐、可切换宽带声学滤波器奠定了基础。[2020-0203]
This work reports on the first demonstration of the frequency tuning and intrinsic polarization switching of film bulk acoustic resonators (FBARs), based on sputtered AlScN piezoelectric thin films with Sc/(Al + Sc) ratio of approx. 30%. A box-like ferroelectric hysteresis behavior of 900 nm-thick Al0.7Sc0.3N sputtered films is obtained, showing a coercive electric field at similar to 3 MV/cm. The fundamental thickness-mode resonance of the bulk acoustic wave (BAW) resonator is measured at 3.17 GHz frequency with an excellent electromechanical coupling coefficient (k(t)(2)) of 18.1%. The FBAR frequency response is studied, in both (i) the linear tuning regime, upon application of DC electric fields below the coercive field; as well as (ii) the polarization switching regime, upon application of electric fields above the coercive field. A large linear tuning range of 215 ppm x mu m/V is obtained in case (i), resulting from the high scandium content. The series resonance frequency of the FBARs is switched ON and OFF in (ii) upon application of 350 V unipolar waveform across the Al0.7Sc0.3N thickness. This is the first demonstration of the intrinsically switchable AlN-based FBARs with a large tuning range; and record high k(t)(2) reported for AlN-based FBARs to date. Furthermore, this work paves the way for realization of tunable and switchable wideband acoustic filters operating at super high frequency ranges (SHF). [2020-0203]