A 4H-SiC trench gate metal-oxide-semiconductor field-effect transistor(UMOSFET)with semi-super-junction shiel-ded structure(SS-UMOS)is proposed and compared with conventional trench MOSFET(CT-UMOS)in this work.The advantage of the proposed structure is given by comprehensive study of the mechanism of the local semi-super-junction structure at the bottom of the trench MOSFET.In particular,the influence of the bias condition of the p-pillar at the bottom of the trench on the static and dynamic performances of the device is compared and revealed.The on-resistance of SS-UMOS with grounded(G)and ungrounded(NG)p-pillar is reduced by 52％(G)and 71％(NG)compared to CT-UMOS,respectively.Additionally,gate ox-ide in the GSS-UMOS is fully protected by the p-shield layer as well as semi-super-junction structure under the trench and p-base regions.Thus,a reduced electric-field of 2 MV/cm can be achieved at the corner of the p-shield layer.However,the quasi-intrinsic protective layer cannot be formed in NGSS-UMOS due to the charge storage effect in the floating p-pillar,resulting in a large electric field of 2.7 MV/cm at the gate oxide layer.Moreover,the total switching loss of GSS-UMOS is 1.95 mJ/cm2 and is reduced by 18％compared with CT-UMOS.On the contrary,the NGSS-UMOS has the slowest overall switching speed due to the weakened shielding effect of the p-pillar and the largest gate-to-drain capacitance among the three.The proposed GSS-UMOS plays an important role in high-voltage and high-frequency applications,and will provide a valuable idea for device design and circuit applications.

Xiaojie Wang;Zhanwei Shen;Guoliang Zhang;Yuyang Miao;Tiange Li;Xiaogang Zhu;Jiafa Cai;Rongdun Hong;Xiaping Chen;Dingqu Lin;Shaoxiong Wu;Yuning Zhang;Deyi Fu;Zhengyun Wu;Feng Zhang

College of Physical Science and Technology,Xiamen University,Xiamen 361005,China;Key Laboratory of Semiconductor Material Sciences,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Shenzhen Research Institute of Xiamen University,Shenzhen 518057,China;Jiujiang Research Institute of Xiamen University,Jiujiang 332000,China

半导体学报（英文版）

[1]Xiaojie Wang;Zhanwei Shen;Guoliang Zhang;Yuyang Miao;Tiange Li;Xiaogang Zhu;Jiafa Cai;Rongdun Hong;Xiaping Chen;Dingqu Lin;Shaoxiong Wu;Yuning Zhang;Deyi Fu;Zhengyun Wu;Feng Zhang-.A 4H-SiC semi-super-junction shielded trench MOSFET:p-pillar is grounded to optimize the electric field characteristics)[J].半导体学报（英文版）,2022(12):85-93

UMOSFET,shiel,ungrounded

4H,SiC,super,junction,shielded,trench,pillar,optimize,electric,field,characteristics,gate,metal,oxide,semiconductor,effect,transistor,structure,proposed,compared,conventional,this,work,advantage,given,by,comprehensive,study,mechanism,local,bottom,In,particular,influence,bias,condition,static,dynamic,performances,device,revealed,resistance,reduced,respectively,Additionally,fully,protected,layer,well,under,base,regions,Thus,MV,be,achieved,corner,However,quasi,intrinsic,protective,cannot,formed,NGSS,due,charge,storage,floating,resulting,Moreover,total,switching,loss,mJ,On,contrary,has,slowest,overall,speed,weakened,shielding,largest,drain,capacitance,among,three,plays,important,role,high,voltage,frequency,applications,will,provide,valuable,idea,design,circuit

0.386977