Research On Three-dimensional Physical Simulation Of MEMS Process

Manufacturing of MEMS sensor structures requires complex process flows.If the functional verification of the sensor and the optimization of the device structure are completed only by experimental processing and testing,it will take a lot of time and cost.By using MEMS Computer Aided Design techniques in processing,device optimization and system testing,development time and device production cycles of sensors can be reduced.Commonly used processing methods are: Reactive Ion Etching,"Bosch" process and Low Pressure Chemical Vapor Deposition Process.The simulation model in the process level is studied in this paper.The model realizes the prediction of the processing structure of the sensor structure through process simulation.The basic characteristics of plasma and the formation mechanism of plasma sheath is studied in this paper.A two-dimensional plasma simulation model was established based on particle grid(PIC)algorithm for plasma etching process simulation.Various collision types of particles in plasma are simulated by Monte Carlo collision algorithm.On the one hand,through the plasma simulation model,the particle distribution more in line with physical reality is obtained,which improves the reliability and accuracy of the process simulation model.On the other hand,the research and simulation of plasma can not only understand the underlying physical mechanism of the plasma process,but also help optimize the structural design of the plasma process chamber.Compared with other process simulation models,the transport process of particles in actual processing is simulated.In the three-dimensional process simulation model,the ray tracing algorithm is used to simulate the particle transport process.The updating and evolution of the process surface is achieved by the narrow band level set method.Finally,the deep hole etching and thin film deposition etching experiments are compared with the process simulation results to verify the reliability of the process simulation model.