System Level Co-design Method And Technologies Of Vibrating MEMS With Interface Circuits

Different from integrated circuit design that focuses on electrical characteristics,the design of MEMS has characteristics of multidisciplinary and multi energy domain interaction.Therefore,the collaborative design of MEMS devices with their interface circuits has always faced with great challenges in terms of design efficiency,design flow,and so on.And realizing efficient and rapid simulation of MEMS through system level method has become an important research direction in MEMS design.Design of MEMS devices and interface circuits has high demands in aspects of platform consistency,flow optimization,parameter iteration,and high speed simulation.Based on MuPEN system level modeling and simulation method,a system level design flow of MEMS devices and their circuits is proposed.And taking classical vibrating MEMS as research object,its key technologies and implementation procedure are deeply studied.Main work and innovations of this thesis are as follows:1.Rectangular beam with uniform cross section is main function structure of flexural vibrating MEMS devices.Through analyzing shape functions of beam,system level behavioral modeling theory of beam category components is summarized.Taking nonlinear beam,lateral beam electrode and magnetically actuated beam as examples,modeling procedure of beam category components is introduced.Analytical mathematical models of the components are constructed.And corresponding system level parameterized models are established by utilizing MuPEN modeling method,and verified through different examples.2.Nonlinear beam is the key structure to realize sensing function of resonant MEMS sensors.In order to widen the application field of nonlinear beam component,system level modeling and simulation method of resonant MEMS sensors are studied based on reusable parameterized component library.And typical devices of resonant accelerometer and magnetometer are modeled and simulated.The simulation results show that the design of resonant MEMS sensors can be carried out efficiently and accurately based on system level schematic model.Meanwhile,accuracy of the newly built beam category components is also further verified.3.Existing methods used in extracting parameters of MEMS resonator have shortcomings of low accuracy and efficiency.A method of extracting those parameters through system level modeling and simulation is proposed.This method can improve extraction efficiency without reducing accuracy.The extraction process of this method is discussed through two free-free beam resonators.The accuracy and efficiency of this method are verified by comparing results of system level method with experiment method and FEA method.4.To accomplish rapid iterative design of vibrating MEMS devices with interface circuits,a design idea,which uses fully parameterized low order lumped element model of MEMS devices to collaboratively simulate with interface circuits,is proposed.The process of constructing a fully parameterized system level model is studied through a resonant MEMS pressure sensor.Taking a fully symmetric decoupled z axis MEMS gyroscope as example,the proposed system level design method of vibrating MEMS devices with interface circuits is demonstrated.Simulation results and design process of the device show that the collaborative simulation efficiency with interface circuit of fully parameterized low order model is much higher than that of high order model based on reusable parameterized component library.The simulation efficiency is improved about 300 times.And the relative accuracy is within 9%.Meanwhile,feasibility and efficiency of the system level design method and process proposed in this thesis are proved.In summary,the purpose of this thesis is to improve the efficiency of MEMS+IC collaborative design,study key technologies of system level simulation and design,and optimize system level design flow.Research results of different vibrating MEMS suggest that the proposed MEMS+IC system level collaborative design method can ensure accuracy of simulation,and greatly improve design efficiency.This is of great significance for improving current MEMS design technologies,shortening MEMS product development cycle,and reducing the development cost.