10 kV SiC LBD-MOSFET结构设计与特性研究  

Design and Characteristics of a Novel 10 kV SiC MOSFET Embedding Low Barrier Diode

作　　者：文译[1] 陈致宇 邓小川[1,2] 柏松[3] 李轩[1,2] 张波[1] WEN Yi;CHEN Zhi-yu;DENG Xiao-chuan;BAI Song;LI Xuan;ZHANG Bo(School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu,610054;Institute of Electronic and Information Engineering in Guangdong,University of Electronic Science and Technology of China,Dongguan Guangdong,523808;State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices,Nanjing Electronic Devices Institute,Nanjing,210016)

机构地区：[1]电子科技大学电子科学与工程学院,成都610054 [2]电子科技大学广东电子工程信息研究院,广东东莞523808 [3]南京电子器件研究所宽禁带半导体电力电子器件国家重点实验室,南京210016

出　　处：《电子科技大学学报》2021年第4期520-526,共7页Journal of University of Electronic Science and Technology of China

基　　金：国家科技重点研发计划(2017YFB0102302);广东省自然科学基金(2019A1515012085)。

摘　　要：针对SiC MOSFET体二极管双极退化效应,该文提出了一种集成低势垒二极管的10 kV SiC MOSFET器件新结构(LBD-MOSFET)。该结构通过在一侧基区上方注入N阱,降低了漏源间的电子势垒,从而在元胞中形成一个低势垒二极管(LBD)。当LBD-MOSFET在第三象限工作时,低的电子势垒使LBD以更低的源漏电压开启,有效避免了体二极管开通所导致的双极退化效应。二维数值分析结果表明,SiC LBD-MOSFET的击穿电压达13.5 kV,第三象限开启电压仅为1.3 V,相比传统结构降低48%,可有效降低器件第三象限导通损耗。同时,由于LBD-MOSFET具有较小的栅漏交叠面积,其栅漏电容仅为1.0 pF/cm^(2),器件的高频优值为194 mΩ·pF,性能相比传统结构分别提升了81%和76%。因此,LBD-MOSFET适用于高频高可靠性电力电子系统。In this paper,a novel 10 kV SiC MOSFET embedding low barrier diode(LBD-MOSFET)is proposed and researched to solve the bipolar degradation effect in SiC MOSFET.The low barrier diode(LBD)in the cell is formed by introducing an N_well above the P_base region on one side,which reduces the electron barrier between the drain and the source.When the LBD-MOSFET works in the third quadrant,the low electronic barrier makes the LBD turn on with a lower source-drain voltage,thus effectively avoiding the bipolar degradation effect caused by the turn-on of the body diode.2D numerical analysis results show that the breakdown voltage of the SiC LBD-MOSFET reaches 13.5 kV.In the third quadrant,the turn-on voltage is only 1.3 V,which is 48%lower than the traditional structure and effectively reduces the conduction loss of the device.At the same time,since the gate-drain overlap area of the LBD-MOSFET is reduced compared to the traditional MOSFET,the Cgd is only 1.0 pF/cm^(2) and the high-frequency merit value of the device is 194 mΩ·pF,which are reduced by 81%and 76%compared with the traditional MOSFET,respectively.Therefore,the LBD-MOSFET is suitable for high-frequency and high-reliability power electronic systems.

关 键 词：击穿电压 栅漏电容 低势垒 碳化硅 第三象限 

分 类 号：TN386[电子电信—物理电子学]