標題: Numerical Study of 4H-SiC UMOSFETs with Split-Gate and P plus Shielding
作者: Jiang, Jheng-Yi
Wu, Tian-Li
Zhao, Feng
Huang, Chih-Fang
國際半導體學院
International College of Semiconductor Technology
關鍵字: silicon carbide;UMOSFETs;split gate;P plus shielding;current spreading layer
公開日期: 1-Mar-2020
摘要: In this paper, performances of a 4H-SiC UMOSFET with split gate and P+ shielding in different configurations are simulated and compared, with an emphasis on the switching characteristics and short circuit capability. A novel structure with the split gate in touch with the P+ shielding is proposed. The key design issues for 4H-SiC UMOSFETs are trench gate dielectric protection and reverse transfer capacitance Crss reduction. Based on simulation results, it is concluded that a UMOSFET with a gate structure combining split gate grounded to the trench bottom protection P+ shielding layer and a current spreading layer is achieved to yield the best compromise between conduction, switching, and short circuit performance. The split-gate design can effectively reduce Crss by shielding the coupling between the gate electrode and the drain region. The P+ shielding design not only protects the oxide at trench bottom corners but also minimizes the short channel effect due to drain-induced barrier lowing and the channel length modulation. Trade-off of the doping concentration of current spreading layer for UMOSFET is also discussed. A heavily doped current spreading layer may increase Crss and influence the switching time, even though R-ON,R-SP is reduced.
URI: http://dx.doi.org/10.3390/en13051122
http://hdl.handle.net/11536/154089
DOI: 10.3390/en13051122
期刊: ENERGIES
Volume: 13
Issue: 5
起始頁: 0
結束頁: 0
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