Simulation and Optimization of Ni/Partial Pattern-ZnO/Si Delayed Linear SAW Devices

Surface acoustic wave (SAW) devices occupy an essential position in wireless communication due to their wireless, passive properties. As information technology advances, there is a growing demand for SAW-based sensors with higher frequency and better performance. Piezoelectric layer patterned (pattern by etching) structure SAW devices have drawn much attention due to their superior performance. In this research, simulations and experiments on Ni/partial pattern-ZnO/Si delayed linear SAW devices under Sezawa mode were conducted, and the effect of the piezoelectric layer patterned on insertion loss (S_21) was optimized. Results show that the Sezawa mode achieves high frequencies of about 2.6 GHz and reducesS_21of devices when the piezoelectric layer is etched away by 35 nm. Simulation data show that the optimum value ofS_21is −12.1 dB, which is about 71.8% lower than unetched −42.9 dB. Ni/partial pattern-ZnO/Si delayed linear SAW devices were fabricated based on simulated model parameters. SAW device test results show that the optimumS_21value is −24.6 dB, which is about 40% lower than the unetched −41.0 dB. Therefore, SAW devices based on piezoelectric layer patterned structures with coupling of bulk acoustic wave (BAW) and SAW (BAW/SAW) can effectively reduceS_21. The improvement of Sezawa mode performance SAW devices is of great significance for the development of the SAW-based sensor field.