Research On Power Capacity Of Solid Mount Bulk Acoustic Wave Resonator

With the development of the fifth-generation wireless communication technology in recent years,there will be two major changes in radio frequency signals:first,high-frequency communications,5G will use frequency bands above 3GHz;second,the number of frequency bands will increase.It can be seen that the high power capacity and micro-miniaturization of RF front-end passive components will become a new development trend.As a new type of RF MEMS device,the bulk acoustic wave resonator has the advantages of low insertion loss,large Q value,high operating frequency,high power capacity,and compatibility with CMOS technology.Therefore,it has made rapid progress in the field of wireless communications.In this paper,the solid mounted resonator?SMR?is used as the basic research unit to explore the laws of its electrical and thermal performance.It has laid the foundation for the high power capacity micro-miniaturization trend of RF front-end passive devices.Firstly,according to the working principle of bulk acoustic wave resonators,the Mason and MBVD models of solid-state assembled bulk acoustic wave resonators were established using ADS simulation software.At the same time,the finite element model of the resonator was built using Comsol Multiphysics.Physical field analysis,and study the effect of the materials used in each layer of the device on its performance.In the electrical simulation,it was found that when the thickness of the top electrode was 100nm,the four electrode materials of W,M,Al,and Pt had the lowest resonance frequency?2.642 GHz?and the highest resonance frequency?3.958 GHz?of Al.When the top electrode mass is the same,the electrode material with larger acoustic impedance will produce less parasitic resonance.At the same time,the influence of the area changes of the top electrode and the bottom electrode on the electrical performance of the device was studied.The simulation results show that the reduction of the electrode area will increase the parasitic resonance near the resonance point.Change the area of the top electrode,and produce more significant horizontal stray signals near the resonance point;In the thermal simulation,the thermal performance of solid-state assembled and homogeneous resonators is compared with the change in thermal power.The thermal power of solid-mounted assembled resonators increases by 0.1W maximum.The steady-state temperature has increased by an average of 4.375K,and the maximum thermal stress has increased by 1Mpa.The average steady-state temperature has increased by an average of212.5K,and the maximum thermal stress has increased by 1.68×10⁷GPa.Based on the simulation,the thermal performance of the solid-state assembled resonator is optimized by doping the piezoelectric layer with Mg and Zr.The simulation results show that as the doping concentration of Mg and Zr increases,the maximum steady state temperature and maximum thermal stress of the device decrease When the total doping concentration of Mg and Zr is 15%,the thermal performance of the device is the best.When the thermal power is 1W,the maximum steady-state temperature is 323K,and the maximum thermal stress is 52.4MPa.Secondly,based on the theoretical simulation analysis of solid assembled resonators,this paper focuses on the preparation of the film materials.The effects of magnetron sputtering power and gas pressure on the growth of Mo,W and AlN films were studied.The Mg and Zr doped aluminum nitride films were prepared according to the optimal process conditions,and the 2?change trend of the?002?crystal orientation of the AlN film was obtained.The effects of power,pressure and temperature of chemical vapor deposition on the growth of SiO₂ films were also studied.Finally,combining the theoretical analysis and simulation results of a bulk acoustic wave resonator,a high power capacity SMR device was fabricated using a MEMS processing platform,and its performance test results were obtained.The parallel resonance frequency of the final device is 1.5019GHz,the effective electromechanical coupling coefficient of the device is 5.728%,and it can withstand signals exceeding30dBm.