FEM analysis of Pt/Scx Al1-x N/Al2 O3 One Port Surface Acoustic Wave Resonators

Abstract

The effect of the thickness of platinum electrode Pt(w), and Scandium doping concentration Sc(x) on the characteristics, and performance of one-port SAW resonator are studied using the finite-element method (FEM). The computed Rayleigh wave velocity (Vsaw) agreed well with theoretical and experimental data. With the increasing of electrode thickness from 0.09 μm to 0.21 μm, Rayleigh mode resonance frequency decreases from 2.46 GHz to 1.78 GHz. Both quality factors (Q) and frequency response (S11) of resonators will increase sharply with the increase of the Pt(w, exhibiting 9% and 202% improvement respectively. After that, we study the influence of scandium dopant Sc(x) on the admittance (Y11), the quality factor (Q) and the frequency response (S11). The resonance frequency and quality factor (Q) decreased as the concentration of Scandium Sc(x) increased from zero to 37.5 %, whereas the parameter S11 improved by - 12.12 dB at a concentration of 25% scandium. The results show that by combining electric loading of metallic electrodes with a high scandium doping concentration Sc(x), a high-performance SAW resonator may be achieved. According to the findings, Pt/ ScxAl1-xN /Al2O3 structures with Pt(w) of 0.21 μm and 25% Sc(x) might be utilized in SAW devices for high frequency and temperature sensor applications.