4H-SiC平面型和沟槽型MOSFET高低温下的特性  

Characterization of 4H-SiC Planar MOSFETs and Trench MOSFETs at Cryogenic and High Temperatures

作　　者：祁金伟 田凯 张勇[1] 张安平 Qi;Jinwei;Tian Kai;Zhang Yong;Zhang Anping(State Key Laboratory of Electrical Insulation and Power Equipment,Xi′an Jiaotong University,Xi’an 710049,China;Tsinsic Semiconductor Co.,Ltd.,Dongguan 523808,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]东莞清芯半导体科技有限公司,广东东莞523808

出　　处：《微纳电子技术》2020年第8期609-616,共8页Micronanoelectronic Technology

基　　金：National Key Research and Development Program(2017YFB1200902-09);Dongguan Introduction Program of Leading Innovative and Entrepreneurial Talents。

摘　　要：采用自对准工艺制备了1.2 kV4H-SiC平面型和沟槽型MOSFET器件,并在90~490 K的温度范围内对4H-SiC MOSFET器件的静态和动态特性与商用1.2 kV Si IGBT器件的性能进行了对比研究。4H-SiC MOSFET器件的静态特性包括导通电阻(Ron)和阈值电压(Vth),而动态特性则重点研究了开关能量损耗(ESW)随温度的变化。首次在低温下针对与沟道缺陷相关的4H-SiC平面型和沟槽型MOSFET的动态导通电阻退化机理进行了定量化分析。实验结果发现4H-SiC平面型MOSFET器件的开启瞬态的延迟较小短,而4H-SiC沟槽型MOSFET器件表现出显著的开启瞬态延迟和动态导通电阻退化现象,在低温下动态电阻退化现象更为严重。CV特性曲线显示动态导通电阻退化是由于沟槽型器件沟道中与工艺相关的缺陷造成的。随着4HSiC沟槽型MOSFET器件制备工艺的不断成熟,工艺相关的缺陷有望得到缓解,从而从根本上消除动态导通电阻的退化。1.2 kV4 H-SiC planar and trench MOSFETs were fabricated by a self-aligned process,and the temperature dependence of static and dynamic characteristics was compared and investigated with that of commercial 1.2 kV Si IGBTs over a wide temperature range of 90 K to 490 K.The static characterization includes static on-resistances(Ron)and threshold voltages(Vth).The dynamic characterization focuses on the temperature dependence of switching energy losses(ESW).For the first time,the interface traps related degradation of dynamic on-resistance for both 4 H-SiC planar MOSFET and 4 H-SiC trench MOSFET was quantitatively analyzed at cryogenic temperatures.The experimental results show that the turn-on transients of the 4 H-SiC planar MOSFET exhibit a small delay.However,the 4 H-SiC trench MOSFET suffers much longer delay at switch-on process and severe degradation of dynamic on-resistance,especially at lower temperatures.The C-V characteristic curves show that the degradation of the dynamic on-resistance is presumably due to high density process-related interface traps.With continued improvements of the fabrication processes for 4 H-SiC trench MOSFETs,process-related defects will be reduced to eventually eliminate the degradation of the dynamic on-resistance.

关 键 词：4H-碳化硅(SiC) 平面型MOSFET 沟槽型MOSFET 温度效应 动态导通电阻退化 

分 类 号：TN32[电子电信—物理电子学] TN304.24