Design Of 3.3kV IGBT Device

As a representative power device in the field of power electronics,IGBT is is widely used in the field of high voltage power electronics system.In the application scenarios of high voltage field,the turn-off robustness is one of the key factors to measure the performance of IGBT.Therefore,it is of great significance to study the turn-off reliability of IGBT and design a high voltage IGBT device with low on-voltage drop and high reliability.The design of 3.3k V power IGBT uses FS-IGBT(Field Stop IGBT)with carrier storage layer as cellular structure and Variation of Lateral doping(VLD)as terminal structure.Then,a simulation model of the device is established in Sentaurus,and key structural parameters such as N-type buffer layer,P+ region and carrier storage layer are designed and optimized by combining theoretical analysis and simulation verification.The simulation results show that the breakdown voltage of the designed 3.3k V IGBT device is 4400 V,threshold voltage is 5.8V,on-voltage drop is 2.35 V,overshoot voltage is 275 V,turn-off loss is 3050 m J(gate turn-off resistance is 6 ohms,parasitic inductance is100 n H),turn-off loss is all the parameters meet the design specifications.In addition,the mechanism of turn-off reliability of IGBT is studied in the thesis.The results show that the voltage overshoot during turn-off is affected by stray inductance,load current,gate turn-off resistance,temperature and other factors.When the turn-off speed of the device is accelerated,the dynamic avalanche of the device is caused by the large voltage overshoot,which leads to the increase of the peak electric field of the PN junction in the P-type body region and n-drift region of the device,and leads to the further increase of turn-off loss.Therefore,an electric field control layer is added into the device structure to weaken the electric field peak during device turn-off,so as to effectively suppress the number of carriers generated by collision ionization and reduce turn-off loss.The turn-off loss of the optimized structure is reduced by 6% compared with that before improvement,and the turn-off robustness of the device is improved.