一种低功耗4H-SiCIGBT的仿真研究

针对传统沟槽栅4H-SiC IGBT关断时间长且关断能量损耗高的问题,文中利用Silvaco TCAD设计并仿真了一种新型沟槽栅4H-SiC IGBT结构.通过在传统沟槽栅4H-SiC IGBT结构基础上进行改进,在N+缓冲层中引入两组高掺杂浓度P区和N区,提高了N+缓冲层施主浓度,折中了器件正向压降与关断能量损耗.在...     

一种具有低寿命区的阳极短路4H-SiC IGBT仿真研究

传统沟槽型4H-SiC IGBT中关断损耗较大,导通压降和关断损耗难以折中。针对此问题,文中提出了发射极区域含有低寿命区,同时集电区引入阶梯型集电极的LS-IGBT结构来降低器件的关断损耗。通过同时控制集电区注入的空穴载流子数量和P基区载流子的寿命,在基本维持器件击穿电压的前提下降低器件的关断损耗。使用Silvaco Atlas器件仿真工具对改进结构进行特性仿真分析,并与传统结构进行对比。仿真结果显示,在击穿电压一致的前提下,新结构的关断损耗提升了84.5 %,同时器件的导通压降降低了8.3 %,证明了设计思想的正确性。     

1700 V精细沟槽栅IGBT器件设计

为了改善绝缘栅双极型晶体管(IGBT)器件关断损耗和导通压降之间的折中关系,同时降低器件制造成本,基于1 700 V电压平台设计了一种采用精细沟槽栅结构的IGBT。采用TCAD软件进行仿真,研究衬底电阻率、衬底厚度、沟槽栅深度、沟槽栅宽度、载流子存储层注入剂量、沟槽栅元胞结构等因素对精细沟槽栅IGBT器件性能参数的影响,确定了最优工艺参数,并对1 700 V精细沟槽栅IGBT芯片进行流片和封装。测试结果显示,相比普通沟槽栅IGBT模块,1 700 V精细沟槽栅IGBT模块在芯片面积减小34.2%的情况下,关断损耗降低了8.6%,导通压降仅升高5.5%,器件性价比得到了优化。     

杨教授视点 智能电网技术 15kVSiCIGBT的发展及其对电力应用的影响(中)

15-kV SiC IGBT的设计与优化图3给出了15-kVN沟道4H-SiC IGBT的半单元截面图。4H-SiC n⁺衬底上生长有外延层。厚3μm、1×10¹⁹cm^-3掺杂的P+发射极层是第一个外延层。其后是n型底部缓冲层（场塞）,厚5μm,掺杂浓度1×10¹⁷cm^-3,可以防止场击穿,同时实现了较好的性能折中。IGBT的N-漂移层厚150μm,掺杂浓度     

4H-SiC TSOB结势垒肖特基二极管静态特性

为增强器件的反向耐压能力,降低器件的漏电功耗,采用Silvaco TCAD对沟槽底部具有SiO₂间隔的结势垒肖特基二极管(TSOB)的器件特性进行了仿真研究。通过优化参数来改善导通压降(V_F)-反向漏电流(I_R)和击穿电压的折衷关系。室温下,沟槽深度为2.2 μm时,器件的击穿电压达到1 610 V。正向导通压降为2.1 V,在V_F=3 V时正向电流密度为199 A/cm²。为进一步改善器件的反向阻断特性,在P型多晶硅掺杂的有源区生成一层SiO₂来优化漂移区电场分布,此时改善的器件结构在维持正向导通压降2.1 V的前提下,击穿电压达到1 821 V,增加了13%。在1 000 V反向偏置电压下,反向漏电流密度比普通结构降低了87%,有效降低了器件的漏电功耗。普通器件结构的开/关电流比为2.6×10³(1 V/-500 V),而改善的结构为1.3×10⁴(1 V/-500 V)。     

具有异质结体二极管和N包围型P柱的4H-SiC超结MOSFET

利用TCAD仿真研究了一种具有异质结体二极管与N包围型P柱超结的4H-SiC UMOSFET(SJH-MOSFET)。通过在SJH-MOSFET中引入异质结和具有电荷平衡的超结结构,能够有效地优化器件的击穿电压、比导通电阻、反向恢复特性。研究结果表明,薄轻掺杂的电流扩展层(CSL)和N型包围使得耗尽区变窄,并为电流的流动提供了两个扩散路径,其中CSL使得电子快速地水平扩散,而N型包围允许电子可以垂直地流动,改进后结构的耐压提升了13.6%,栅槽底部高电场降低了10.5%,比导通电阻降低了10.5%,开启时间降低了38.4%,关断时间降低了44.7%;体区嵌入P⁺多晶硅与漂移区接触形成异质结体二极管,由于异质结特殊的能带结构,使得体二极管在导通时,P⁺多晶硅里空穴较少地流入到漂移区,使反向恢复电荷降低了42.96%,反向恢复时间降低了4.17%。     

一种新N型射极势垒绝缘栅双极晶体管

本文提出了一种新N型射极势垒绝缘栅双极晶体管。该器件用N型轻掺杂区代替传统的P+区形成空穴势垒,以阻止寄生PNP晶体管空穴分流,从而增强电导调制效应。仿真验证结果显示,该器件对比传统沟槽IGBT,其电流密度和关断损耗分别增加和降低了49%和25%,同时具有相似的击穿电压、关断时间和雪崩能量。此外,该器件具有无限大的跨导,有利于开通和关断。因此,该器件可应用于高压大功率电力电子系统。     

一种双发射极沟槽栅超结IGBT

本文对传统沟槽栅超结IGBT进行了改进,得到一种沟槽栅双发射极超结IGBT,本结构第一个发射极区域和传统IGBT结构一样能够发射电子、接收空穴,在p型柱顶部的第二个发射极区域能够起到空穴分流的作用,在有效地提高器件抑制闩锁的能力的同时,保持了超结IGBT器件的高击穿电压(BVoff)和低关断损耗(Eoss)。仿真显示在VGE=10V的条件下,改进结构的闩锁电流从15000A/cm2 提升至 28300A/cm2,器件的击穿电压为810V,在导通压降为1.2V的条件下,关断损耗为6.5 mJ/cm2。     

阶梯浅沟槽隔离结构LDMOS耐压机理的研究

提出了一种具有阶梯浅沟槽隔离结构的LDMOS.阶梯浅沟槽结构增加了漂移区的有效长度,改善了表面电场及电流的分布,从而提高了器件的击穿电压.借助器件模拟软件Silvaco对沟槽深度、栅长及掺杂浓度等工艺参数进行了优化设计.结果表明,在保证器件面积不变的条件下,新结构较单层浅沟槽隔离结构LDMOS击穿电压提升36%以上,而导通电阻降低14%.     

一种具有部分高介电常数介质调制效应的IGBT

提出了一种具有高介电常数介质填充沟槽的绝缘栅双极晶体管(IGBT)。分析了高介电常数介质调制效应。结果表明,与普通场阻型IGBT相比,该器件的击穿电压提高了8%,通态压降减小了8%,关断损耗降低了11%;在相同通态压降下,该器件的关断损耗降低了35%。在栅极与原HK介质之间增加介电常数更高的介质,进一步提升了该IGBT的性能。与普通场阻型IGBT相比,在相同击穿电压与通态压降下,改进器件的关断损耗降低了57%。     

A novel single gate MOS controlled current saturated thyristor

A novel single gate MOS controlled current saturation thyristor (MCST) device is proposed. In the on-state the MCST operates in thyristor-like mode at low anode voltage and enters the IGBT-like mode automatically with increasing anode voltage, offering a low on-state voltage drop and current saturation capability. Simulation results based on 6.5 kV trench devices indicate the turn-off energy loss of the MCST is reduced by over 35% compared to the IGBT. The saturation current density of the MCST is strongly dependent on the on-set voltage of the p ⁺ buffer/n-well junction, leading to its excellent safe operation area (SOA) and making it suitable for high power applications     

Trench SJ IGBT 的仿真研究

本文对沟槽型超结绝缘栅双极晶体管(trench SJ IGBT)进行了全面的分析,并通过Sentaurus TCAD仿真软件将其与沟槽型场截止绝缘栅双极晶体管(trench FS IGBT)进行了详尽的对比,仿真结果显示,在相同的条件下与trench FS IGBT 相比,trench SJ IGBT 的击穿电压提高了100 V,饱和导通压降降低了0.2 V,关断损耗减少了50%。最后,文章研究了电荷不平衡对trench SJ IGBT 的动静态参数的影响。对各参数和它们对电荷不平衡的灵敏度之间的折中进行了讨论。     

A novel TFS-IGBT with a super junction floating layer

A novel trench field stop (TFS) IGBT with a super junction (SJ) floating layer (SJ TFS-IGBT) is proposed.This IGBT presents a high blocking voltage (>1200 V), low on-state voltage drop and fast turn-off capability. A SJ floating layer with a high doping concentration introduces a new electric field peak at the anode side and optimizes carrier distribution, which will improve the breakdown voltage in the off-state and decrease the energy loss in the on-state/switching state for the SJ TFS-IGBT. A low on-state voltage (VF) and a high breakdown voltage (BV) can be achieved by increasing the thickness of the SJ floating layer under the condition of exact charge balance. A low turn-off loss can be achieved by decreasing the concentration of the P-anode. Simulation results show that the BV is enhanced by 100 V, VF is decreased by 0.33 V (at 100 A/cm2) and the turn-off time is shortened by 60%, compared with conventional TFS-IGBTs.     

Structure oriented compact model for advanced trench IGBTs without fitting parameters for extreme condition: Part II

Compact model for expressing turn-off waveform for advanced trench gate IGBTs is proposed even under high current density condition. The model is analytically formulated only with device structure parameters so that no fitting parameters are required. The validity of the model is confirmed with TCAD simulation for 1.2–6.5 kV class IGBTs. The proposed turn-off model is sufficiently accurate to calculate trade-off curve between turn-off loss and saturation collector voltage under extremely high current conduction, so that the model can be used for system design with the advanced trench gate IGBTs.     

一种带有超结浮空层的槽栅场阻IGBT

本文提出了一种带有超结浮空层的槽栅场阻IGBT,它具有高的击穿电压(>1200V),低的正向压降和快速的关断能力。高掺杂的 SJ 浮空层在阳极侧引入了电场峰的同时优化了器件内载流子分布,带来关态击穿电压提高,开态、开关态能量损耗减少等好处。在保持电荷平衡的前提下,增加 SJ 浮空层的厚度可以提高击穿电压和降低正向压降,降低 P 型阳极浓度可以减少关断损耗。与传统结构相比,新结构击穿电压提高了100V,正向压降降低了0.33V（电流密度为100A/cm2）,关断时间缩短了60%。     

3100 V, asymmetrical, gate turn-off (GTO) thyristors in 4H-SiC

A 2-mm×2-mm, 4H-SiC, asymmetrical npnp gate turn-off (GTO) thyristor with a blocking voltage of 3100 V and a forward current of 12 A is reported. This is the highest reported power handling capability of 37 kW for a single device in SiC. The 5-epilayer structure utilized a blocking layer that was 50 μm thick, p-type, doped at about 7-9×10¹⁴ cm^-3. The devices were terminated with a single zone junction termination extension (JTE) region formed by ion-implantation of nitrogen at 650°C. The device was able to reliably turn-on and turn-off 20 A (500 A/cm²) of anode current with a turn-on gain (I_K/I_{G, on}) of 20 and a turn-off gain (I_K/I_{G, off}) of 3.3