新型SiC沟槽IGBT的模拟研究

发布时间：2018-02-01 23:23

本文关键词： 沟槽IGBT 平面沟槽IGBT 正向导通压降关断损耗折中关系　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳化硅(SiC)是一种具有宽的禁带、高击穿电压、高热导率、高电子饱和速率以及高抗辐照的半导体材料,近年来由于它的优良特性而受到越来越多的关注。SiC功率器件因为很大程度的降低了电子设备的功耗而被称为“绿色能源”器件,推动了“新能源革命”的发展。其在高性能雷达、现代军事电子通讯系统、宇航系统、电磁武器推进系统以及电力电子设备、太阳能发电、高铁牵引设备、混合动力等国防和民用领域有着巨大的应用前景。SiC绝缘栅双极晶体管(IGBT)是一种MOS电压控制和双极晶体管相结合的复合器件,具有MOSFET的高输入阻抗、控制功率小、易于驱动等优点,也具有双极晶体管的大电流密度、低饱和压降的特点。基于这些优点将SiC IGBT器件主要应用于轨道交通、光伏和风能绿色能源、智能电网、移动通信等领域。本文使用Sentaurus TCAD模拟仿真软件主要对SiC沟槽IGBT漂移区的电子分布、正向导通压降和关断损耗以及两者的折中关系进行了研究分析,取得的成果如下:1、对4H-SiC沟槽IGBT器件基本特性进行仿真研究。仿真结果表明沟槽IGBT相比平面IGBT正向导通压降小了一倍,这是由于在沟槽IGBT中消除了JFET电阻以及漂移区中高的电子积累区导致了较强的电导调制效应。但同时沟槽IGBT的关断时间相比平面IGBT增大了约10%。2、研究了4H-SiC沟槽IGBT发射极宽度和沟槽深度对该器件正向导通压降和关断损耗的影响。研究发现,无论发射极宽度还是沟槽深度的变化对漂移区中电子分布、正向导通压降和关断损耗以及两者的折中关系都有影响。发射极宽度的变化对正向导通压降的影响更大,而沟槽深度的变化对关断损耗的影响较大。在发射极宽度和沟槽深度比值相同的条件下,当发射极宽度越窄,沟槽越深得到的正向导通压降和关断损耗的折中更好。在发射极宽度和沟槽深度比值不相同的条件下,当发射极宽度越宽,沟槽越浅得到的正向导通压降和关断损耗的折中更好。总之,不同的结构参数都会使沟槽IGBT漂移区中的载流子浓度发生变化,从而影响正向导通压降和关断损耗及两者的折中关系的变化。漂移区中载流子浓度的变化对正向导通压降的影响较大,这不失为以后研究正向导通压降和关断损耗折中关系提供了方向。3、提出一种结合沟槽和平面的新结构4H-SiC平面沟槽IGBT,并在基本结构参数相同时对沟槽IGBT、平面沟槽IGBT和平面IGBT的漂移区中的电子浓度、正向导通压降和关断损耗以及两者的折中关系进行研究。结果表明,三种结构在具有相同掺杂的情况下,平面沟槽IGBT的正向导通压降和关断损耗都处于两者之间。相比于平面IGBT,平面沟槽IGBT的正向导通压降减小了26.2%,与沟槽IGBT结构相比平面沟槽IGBT的关断损耗减小了2.05%。
[Abstract]:Sic is a semiconductor material with wide bandgap, high breakdown voltage, high thermal conductivity, high electron saturation rate and high radiation resistance. In recent years, more and more attention has been paid to the .SiC power device because of its excellent characteristics, which has greatly reduced the power consumption of electronic equipment, so it is called "green energy" device. Promoting the development of the "New Energy Revolution" in high-performance radar, modern military electronic communication systems, aerospace systems, electromagnetic weapons propulsion systems and power electronics equipment, solar power generation, high-speed rail traction equipment, Sic insulated gate bipolar transistor (IGBT) is a combination of MOS voltage control and bipolar transistor. It has high input impedance of MOSFET and low control power. It also has the advantages of high current density and low saturation voltage drop of bipolar transistors. Based on these advantages, SiC IGBT devices are mainly used in rail transit, photovoltaic and wind energy green energy, smart grid, etc. In this paper, Sentaurus TCAD simulation software is used to analyze the electronic distribution, forward on-off pressure drop, turn-off loss and the eclectic relationship of IGBT drift region in SiC grooves. The results obtained are as follows: 1. The basic characteristics of 4H-SiC grooves IGBT devices are simulated and studied. The simulation results show that the grooved IGBT is twice as small as the planar IGBT forward on-drop. This is due to the elimination of the JFET resistance in the grooved IGBT and the high electron accumulation in the drift region, which leads to a strong conductivity modulation effect. But at the same time, the turn-off time of the grooved IGBT is increased by about 10. 2 compared with the plane IGBT. The 4H-SiC grooves IGBT generation is studied. The effects of emitter width and groove depth on the forward on-pressure drop and turn-off loss of the device are investigated. Both the width of emitter and the depth of grooves have an effect on the electron distribution, forward conduction pressure drop, turn-off loss and the eclectic relationship in the drift region, and the change of emitter width has a greater influence on the forward conduction pressure drop. When the ratio of emitter width to groove depth is the same, the narrower the emitter width is, The deeper the groove, the better the trade-off between forward conduction pressure drop and turn-off loss. When the emitter width and groove depth ratio are different, the wider the emitter width, The shallower the groove, the better the compromise between forward on-pressure drop and turn-off loss. In short, different structural parameters will change the carrier concentration in the IGBT drift region of the grooves. Thus, the change of forward conduction pressure drop, turn-off loss and the compromise between them are affected greatly by the change of carrier concentration in drift region. This provides a direction for further study on the compromise between forward on-pressure drop and turn-off loss. A new structure, 4H-SiC planar grooves, is proposed to combine grooves with plane, and the grooves and planar grooves IGBT with the same basic structure parameters are proposed. And the electron concentration in the drift region of planar IGBT, The forward conduction pressure drop, turn-off loss and the compromise between them are studied. The results show that the three structures have the same doping, The forward on-pressure drop and turn-off loss of planar grooved IGBT are both between them. Compared with plane IGBT, the forward on-off pressure drop of planar grooved IGBT is reduced by 26.2, and the turn-off loss of planar grooved IGBT is reduced by 2.05 compared with the structure of grooved IGBT.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN322.8;TN304.24

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