Design And Research Of Innovative Trench Gate IGBT

The trench gate IGBT eliminates planar gate IGBT’s JFET resistance component when turned on,thereby it has lower on-state voltage drop than planar gate IGBT.When trench gate IGBT is turned on,the gate is integrated inside the IGBT,so it has large channel density,thus the on-state current of the device can be increased.Since aforementioned advantages,trench gate IGBT has played an important role in the field of power electronics,experts and scholars have continued to optimize its structure and characteristics.Starting from the research of innovative trench gate IGBTs,this thesis designs an SFP-IGBT that integrates PMOS and SBL structures on the basis of fully understanding the advantages and limitations of various innovative structures to further optimize device performance.The main research contents are as follows:1.Based on the SFP-IGBT structure,this thesis introduces the PMOS structure in the floating P-type area,which increases the additional discharge path of the hole current,reduces the Miller capacitance and displacement current of the device,and optimizes the traditional SFP-IGBT’s switching characteristics.In addition,the SBL structure is introduced into the P-type base region to further enhance the accumulation of carriers,reduce the on-state voltage drop of the device,and optimize the relationship of on-state voltage drop and turn-off loss.In order to specifically illustrate the degree of optimization of the proposed structure in terms of performance,this thesis also designs four comparison structures.After simulation and comparison,the structure proposed in this thesis has the best breakdown characteristic compared to the other four structures,and it has the smallest on-state voltage drop,Miller capacitance and displacement current.Moreover,the on-state power loss E_on during turn-on process,turn-off power loss E_off,the power loss E_i,off of the carrier extraction process,and the gate-driving loss E_driveduring the turn-on process of the structure proposed in this thesis are respectively lower than those of the traditional SFP-IGBT by 77.1%,4.5%,84.5%,51.0%,which comprehensively improves the performance of traditional SFP-IGBT.2.This thesis also designs the process flow of the proposed structure,and optimizes relevant parameters of the P-type base region,the N-type field stop layer,the N-type epitaxial layer,the floating P-type region,and the N-type carrier storage layer by process simulation,and obtains cell that meets the design criteria finally.After that,this thesis designs a terminal structure,and finally designs the layout of the entire IGBT chip.The IGBT designed in this thesis has a breakdown voltage of 1356V,a threshold voltage of 4.037V,an on-state voltage drop of 1.037V at a rated current of 15A,and an on-state current density of 150A/cm²,and has a good V_on-E_offtrade-off relationship.The breakdown voltage of the terminal structure is 1392V.