Design And Simulation Of Trench FS-IGBT

With the rapid development of science and technology,the electrical field has increasingly higher performance requirements for power electronic devices.As an important power electronic device,IGBT's performance in various aspects is also constantly improving.People constantly improve the structure of IGBTs.The result is that the device size and power consumption are getting smaller and smaller,and the performance and trade-off characteristics are becoming more and more superior..The Trench-FS IGBT is an advanced structure in current IGBT.The field stop structure can narrow the overall size of the device,shorten the existence time of the trailing current and reduce the turn-off power consumption.The device's trench gate structure removes the JFET region of the MOS portion,reducing the drift region resistance and reducing the turn-on voltage.Therefore,this dissertation designs and simulates Trench-FS IGBT devices.Thesis includes the following main content:Firstly,the paper compared the effect of different process parameters on device performance through simulation experiments.The simulation results show that for the threshold voltage,the main influence parameters are the oxide thickness of the gate and the doping concentration of the P-base region.For the breakdown voltage,the main influencing parameters are the effective thickness and doping concenrration of the drift region and the doping concentration of the field stop layer.For the turn-on voltage,the main influencing parameters are the doping concentration of the P base region and the field stop layer.For the turn-off time,the main influence parameter is the doping concentration of the P+ region in the collector terminal.Afterwards,a Trench-FS IGBT was designed based on the simulation results.The device model was established through the Sentaurus TCAD process module and the electrical characteristics were tested.The test results show that the threshold voltage is 4.8V,the turn-on voltage is 2.76V,the breakdown voltage is 1488V and the turn off time is 160ns.The device we designed meets the requirements and it is important to control the process parameters properly.An important task of IGBT research is to develop its compact model.In an actual IGBT,the channel of MOS(in the P-base region of the IGBT)adopts variable doping.However,uniform doping is often used to describe the channel characteristics in compact models.Therefore,we hope to compare the performance of IGBTs with gradient and uniform doping.In addition,we use a Step doping channel to approximate a Gradual channel.The results show that there is a gap between Const model and actual IGBT,and Step model can better simulate the channel characteristics.So two MOS with different threshold voltage can be used to reasonably describe the actual channel in the IGBT.