Analysis And Design Of SOI Based High Voltage Low Loss Lateral IGBT

High voltage power semiconductor devices take on the function of energy control and power conversion.It is very important in power electronic system.Due to the advantages of easy integration and control,high voltage lateral MOS type power devices are widely used in high voltage power integrated circuits?HVICs?.lateral insulated gate bipolar transistor based on Silicon-on-insulator?SOI-LIGBT?has become a hotspot of research because of its advantages caused by conductance modulation effect,such as low on-state loss.However,conventional high voltage SOI-LIGBT has some problems,such as on-state voltage drop and switching loss which are not optimized.And it is difficult to meet the development of HVICs.Aiming at the problems of conventional SOI-LIGBT structure,two novel types of high voltage SOI-LIGBT structurs are studied in this thesis.The main contents of this thesis are as follows:1.A type of two-dimensional SOI-LIGBT structures with split-gate trench are proposed,including a structure with P-float region?TSG-LIGBT?and the other structure with integrated p-MOS?PTSG-LIGBT?.TSG-LIGBT structure can not only obtains additional hole potential barrier,but also reduce the Miller capacitance(C_GC)and improve the tradeoff between on-state drop(V_CEON)and turn-off loss(E_OFF).The p-float region is set in TSG-LIGBT structure to improve the breakdown voltage.The simulation results show that when J_C=100A/cm²,the V_CEON of the new structure is 19%lower than that of the conventional structure.The C_GC of the new structure drops 56.6%compared with that of the conventional structure at V_CE=20V.And the E_OFF of the new structure reduces by 59% compared with that of the conventional structure at V_CEON=2.09V.In addition,the simulation results also show that the tradeoff between V_CEON and E_OFF can be improved by reducing the length of P-base?L_b?or increasing the doping concentration of CS layer(N_CS).PTSG-LIGBT structure is based on TSG-LIGBT structure and integrated with p-MOSFET structure.Therefore,PTSG-LIGBT structure can achieve low power consumption.Due to the potential clamping effect of p-MOSFET structure,the saturation current of the PTSG-LIGBT structure is lower than that of the conventional structure.Therefore,the shortcircuit safe operating area is improved.The simulation results show that the E_OFF of the new structure reduces by 38%compared with that of the conventional structure at V_CEON=2.14V.When the V_CE is 15V,the saturation current of the new structure is 31%lower than that of the conventional structure.When P_C=3×10¹⁸cm^-3 and the V_CE=300V,the failure time of the new structure is 5?s longer than that of the conventional structure.2.A type of three-dimensional SOI-LIGBT structure with split-gate trench?3d-TSGLIGBT?is proposed.3d-TSGLIGBT structure is proposed by transferring the trench and P-float region in the TSG-LIGBT structure to the direction perpendicular to the paper surface.It can achieve low V_CEON and reduce C_GC,and obtain the more optimized V_CEONEON and E_OFF tradeoff characteristics than that of the conventional structure.The simulation results show that when J_C=100A/cm²,the V_CEON of new structure is 25%lower than that of the conventional structure.The C_GC of the new structure reduces by 31%compared with that of the conventional structure at V_CE=20V.When V_CEON=2.1V,the E_OFF of the new structure drops by 66%compared with that of the conventional structure.