Research On SiC Power Device Modeling

With the further development and research of the third-generation power semiconductor material,the material properties of the silicon carbide due to its wide band gap,high breakdown field,high thermal conductivity and high saturation carrier velocity have been explored.Different from the traditional Si power MOSFET,the SiC power MOSFET has the higher breakdown voltage,the higher operation temperature and the much faster switching frequency.To improve the effective and reduce the damage to the elements and the circuit,the model of the SiC power MOSFET is widely used during the design and experiment of the circuit.The model of the SiC power MOSFET can be divided into five different types-the behavioral model,the semi-physics-based model,physics-based model,semi-numerical-based model and numerical-based model.They have different advantages and disadvantages in its operation.For the application in circuit simulation and the combination to the element design,the compact model based on the physical meaning is proposed in this paper.Firstly,based on the research of the basic models,structures and characteristics of SiC JBS and MOSFET,the improved modeling equations of the current source,capacitances and static elements are proposed.Secondly,the various experiments of the SiC power MOSFET and SiC JBS of several types have been taken.It is used to set the initial value and the range of the parameter.Different from the model with the data in datasheet,modeling with experiment result is more meaningful.Specifically,the 600V and 1200V SiC power MOSFET and SiC JBS are used for modeling in this paper.They are described in Verilog-A and each of the equation has its physical meaning to meet the design of the device.And the model is verified by output characteristic and the switch characteristics measured by the double pulse test,such as the turn on and turn off time and the waveform of the gate voltage and drain voltage.Generally,the compact circuit simulator models of the SiC power devices based on the fabrication process and accurate data from test are proposed in this paper.It is the connection of the device and circuit design and it has good guidance value to the application circuit.