FEM Simulation Analysis of AlN/SiO2/Si Multilayer Structure and Effect of IDT Configuration on SAW Propagation Modes and Characteristics

In this paper, Finite Element Method (FEM) simulation analysis of a CMOS compatible AlN/SiO
₂
/Si SAW device is performed to investigate the Surface Acoustic Wave (SAW) modes and their propagation characteristics. A SAW resonator was simulated based on piezoelectric thin film of Aluminum Nitride (AlN) on passivated silicon (SiO
₂
/Si) substrate. The SAW properties of AlN film on SiO
₂
/Si were analyzed with two composite structures: (IDT)/AlN/SiO
₂
/Si and AlN/(IDT)/SiO
₂
/Si, and they revealed some good SAW properties. The maximum value of k
²
is almost same for both SAW modes with both IDT configurations, but on different values of t
_AIN
/λ and t
_SiO2
/λ. The results stipulate a theoretical basis for further application on high frequency SAW devices. The proposed SAW device based on AlN/SiO
₂
/Si structure have potential applications in integrated sensing applications.