【作者】 苏伟；

【导师】 罗小蓉；

【作者基本信息】 电子科技大学 ， 微电子学与固体电子学， 2022， 硕士

【摘要】 基于SOI（Silicone On Insulator,绝缘体上硅）材料的LIGBT（Lateral Insulated Gate Bipolar Transistor,横向绝缘栅双极晶体管）具有高输入阻抗,大功率密度的优点,被广泛应用于功率集成电路中。LIGBT导通压降V_on和关断损耗E_off的折中关系始终是研究的热点问题。增大器件的饱和电流密度J_sat可以提高器件的驱动能力,然而高的J_sat会使器件发生短路时的局部功耗增大,从而导致器件短路时间t_sc退化。因而饱和电流密度J_sat和短路时间t_sc的折中关系也是需要优化的重要问题。针对以上两个问题,本文提出了两种新型SOI LIGBT器件。1.提出一种阴极具有集成双MOS的SOI LIGBT器件（IDM SOI LIGBT）。新器件结构在传统LIGBT旁集成了两个MOS管（M1和M2）。新结构大大降低了正向导通压降,提高了饱和电流能力和短路能力。新结构通过集成M1和M2以控制常规LIGBT区域阴极寄生二极管D1:器件正向导通时,寄生二极管D1开启,增强器件的电导调制效应,降低导通压降,增大饱和电流密度;当器件处于短路状态时,随着温度升高,D1关闭,使器件免疫闩锁效应,增强器件的短路能力。仿真结果表明,与传统SOI LIGBT相比,新器件的导通压降降低了68%,饱和电流密度提高了155%,短路时间增加了247%。尽管新结构增强电导调制效应会导致器件关断损耗增大,然而由于开启功耗和导通功耗小,因而在开关频率为10k Hz、25 k Hz和50k Hz的条件下,新结构的总功耗相比于传统SOI LIGBT分别降低了39.9%,39.6%和38.9%。2.提出一种具有PNP结构的集成双MOS SOI LIGBT器件（PIDM SOI LIGBT）。新结构在IDM SOI LIGBT的基础上,在主LIGBT阴极区引入PNP结构。当PNP结构的N型基区在高阳极电压下耗尽时,PNP结构可以充当空穴的快速抽取通道,在几乎不降低器件电流能力的同时,改善器件的短路能力和关断损耗。在关断过程中,PNP结构可以同时减少电压增大时间和电流减小时间,降低关断损耗E_off;在短路过程中,PNP结构可以降低局部空穴浓度,从而降低了局部空穴焦耳热,使器件内部的热量分布更均匀,从而提高了器件的短路时间t_sc。仿真结果表明,新结构相比于传统SOI LIGBT关断损耗降低9.4%,导通压降降低55%,总功耗在开关频率为10k Hz、25 k Hz和50k Hz下分别降低49%,53%和57%;饱和电流密度增大141%,短路时间增大457.4%,实现了优化的J_sat-t_sc折中关系。更多还原

【Abstract】 LIGBT（Lateral Insulated Gate Bipolar Transistor）based on SOI（Silicone On Insulator）material has the advantages of high input impedance and high power density.It is widely used in power integrated circuits（PIC）.The trade-off between on-state voltage drop(V_on)and turn-off loss(E_off)has always been a hot research issues.Increasing the saturation current density J_sat of the device can improve its driving ability,but high J_satwill increase the local power consumption in case of short circuit,leading to the decrease in short-circuit time(t_sc).Therefore,the trade-off between saturation current density(J_sat)and short-circuit time t_sc is also an important concern.In view of the above two issues,two new SOI LIGBTs are proposed in this thesis.1.An SOI LIGBT device with integrated double MOS in cathode side（IDM SOI LIGBT）is proposed.The new device introduces two integrated MOSFETs of M1 and M2.The new structure focuses on improving on-state voltage drop,saturation current capability and short circuit capability.By integrating M1 and M2,the cathode parasitic diode D1 in conventional LIGBT region is turned on when the device is forward conduction,enhancing the conductance modulation effect,thus reducing the V_on and increasing J_sat.When the device is in the short-circuit state,D1 is turned off with the temperature rising,so that the device is immune to latch-up effect,which enhances the short-circuit ability.The simulation results show that compared with traditional SOI LIGBT,the V_on is reduced by 68%,J_sat is increased by 155%,and t_sc is increased by 247%.For the new device,although the enhanced conductance modulation effect leads to increasing in E_off,towing to small turn-on loss and conduction loss,the whole power consumption of the new structure reduces by 39.9%,39.6%and 38.9%compared with traditional SOI LIGBT,when the switching frequencies are respectively 10k Hz,25khz and 50k Hz.2.An integrated double MOS SOI LIGBT device with PNP structure（PIDM SOI LIGBT）was proposed.The new structure introduces PNP structure on the basis of IDM SOI LIGBT,which can be compatible with p-well and N-buffer manufacturing processes.When the N-type base region of the PNP structure is depleted under a large anode voltage,the PNP structure can act as a hole fast extraction path,which optimizes short-circuit time and turn-off loss without significant degradation the strong current capability.In the turn-off process,PNP structure can shorten the time of voltage rise and current fall to reduce the turn-off loss E_off;In the short-circuit process,PNP structure can reduce the local hole concentration,thus reducing the local hole joule heat,so that the heat distribution in the device is relatively uniform and the short-circuit time t_sc is improved.The simulation results show that compared with traditional SOI LIGBT,the E_off and V_on are reduced by9.4%and 55%,so that the total power consumption of the new structure is reduced by49%,53%and 57%at switching frequencies of 10k Hz,25khz and 50k Hz,respectively.At the same time,the J_sat increases by 141%and the t_sc increases by 378.9%,which means the new structure achieves a good J_sat-t_sc compromise relationship.更多还原