Miniature Pressure Sensor System-level Modeling And Simulation

The design methodology and CAD tools are key important for the industrialization of MEMS. For the nature of mixed-signal and multiple energy domains, system-level design methodology and modeling tools of MEMS should be carefully considered.MEMS pressure sensors are widely used in many fields and have bright prospect. However, it is difficult to simulate the system behavior of pressure senor because the space-continuous deflection of elastic diaphragm must be modeled. In the thesis, a modeling methodology is presented for description of space-continuous models, where partial differential equations are used. With this method, the piezoresistive and capacitive pressure sensors can be modeled and simulated in EDA tools. The main contents in this thesis are described as follows:1. Based on Multi-Port-Element Network (MuPEN) method, the modeling criterion of MEMS component is established. All the models are coded in analog hardware description language (HDL). The emphasis is put on how to change partial differential equations which the HDL does not support directly to ordinary differential equations.2. The modeling methodology of piezoresistor and elastic diaphragm is studied. Based on the piezoresistive effect in single crystal and polycrystalline silicon, the parameterized behavioral model of piezoresistor is established. According to the theory of plates and shells, small deflection and large deflection models of diaphragm in qusi-static situation are eatabished using energy method. Meanwhile, partial differential equations are usd for modeling dynamic behavior of diaphragm.3. Based on the behavioral model of diaphragm and piezoresistor, the system level model of piezoresistive and capacitive pressure sensor together with processing circuitry is established and simulated. Comparing the simulation results with FEA method or fabrication testing, it indicates that this method is efficient to perform analysis of system performance rapidly and accurately.