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Low Resistance 3.3kV 4H-SiC Trench Shielded DMOSFET

Trench Shield 구조를 갖는 3.3kV급 저저항 4H-SiC DMOSFET

  • Cha, Kyu-hyun (Dept. of Electronics Engineering, Sogang University) ;
  • Kim, Kwang-su (Dept. of Electronics Engineering, Sogang University)
  • Received : 2020.06.16
  • Accepted : 2020.06.24
  • Published : 2020.06.30

Abstract

In this paper, we propose a TS-DMOSFET(Trench Shielded DMOSFET) structure in which P+ shielding region is formed in a deeper region than C-DMOSFET(Conventional DMOSFET) and S-DMOSFET(Shielded DMOSFET). Using TCAD simulation to compare the static characteristics of TS-DMOSFET with C- and S-DMOSFET. As for the structure proposed, the doping is followed by the source trench process. Despite the fact that it is a SiC material, this allows it to form a P+ shielding region in a deep area. Followed by completely suppressing the reach-through effect. As a result, when the breakdown voltage of the three structures is 3.3kV, the Ron of TS-DMOSFET is 9.7mΩ㎠. Thus, it is 68% and 54% smaller than the Ron of C-DMOSFET and S-DMOSFET respectively.

본 논문에서는 Trench를 이용하여 기존 C-DMOSFET(Conventional DMOSFET)과 S-DMOSFET(Shielded DMOSFET) 구조보다 더 깊은 영역에 P+ shielding을 형성한 TS-DMOSFET(Trench Shielded DMOSFET) 구조를 제안하였으며 TCAD 시뮬레이션을 통해 C- 및 S-DMOSFET 구조와 전기적 특성을 비교하였다. 제안한 구조는 Source에 Trench를 형성한 후 도핑을 진행하므로 SiC 물질 특성과 관계없이 깊은 영역에 P+ shielding을 형성할 수 있다. 이로 인해 P-base에 인가되는 전압이 감소하여 리치스루 효과가 완화되었다. 그 결과 세 구조 모두 3.3kV의 항복 전압을 가질 때 제안한 구조의 온저항은 9.7mΩ㎠으로 C-DMOSFET과 S-DMOSFET의 온저항인 30.5mΩ㎠, 19.3mΩ㎠ 대비 각각 68%, 54% 개선된 온저항을 갖는다.

Keywords

References

  1. Huang Runhua et al., "Design and fabrication of a 3.3kV 4H-SiC MOSFET," Journal of Semiconductors, Vol.36, No.9, 2015. DOI: 10.1088/1674-4926/36/9/094002
  2. B. J. Baliga, "Fundamentals of Power Semiconductor Devices," NY, USA: Springer, pp.23-166, 2010.
  3. G. De Martino, F. Pezzimenti, F. G. Della Corte, G. Adinolfi and G. Graditi, "Design and Numerical Characterization of a Low Voltage Power MOSFET in 4H-SiC for photovoltaic Applications," 2017 13th conference on Ph. D. Research in Microelectronics and Electronics (Prime), IEEE pp.221-224, 2017. DOI: 10.1109/PRIME.2017.7974147
  4. H. Okumura, H. Harima, Prof. T. Kimoto, M. Yoshimoto, H. Watanabe, T. Hatayama, H. Matsuura, T. Funaki and Y. Sano, "Blocking Characteristics of 2.2 kV and 3.3 kV-Class 4H-SiC MOSFETs with Improved Doping Control for Edge Termination," Materials Science Forum, Vol.778-780, pp915-918, 2014. DOI: 10.4025/www.scientific.net/msf.778-780. 915
  5. A. Poggi, F. Bergamini, S. Solmi, M. Canino, and A. Carnera, "Effects of heating ramp rates on the characteristics of Al implanted 4H-SiC junctions," Appl. Phys. Lett., vol.88, no.16, pp.162106, 2006. https://doi.org/10.1063/1.2196233
  6. W. Ni, X. Wang, M. Xu, M. Li, C. Feng, H. Xiao, W. Li, Q. Wang, H. Schlichting and T. Erlbacher, "Design and Fabrication of 3300V 100mΩ 4H-SiC MOSFET with Stepped p-body structure," 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China, IEEE, pp.50-53, 2019. DOI: 10.1109/SSLChinaIFWS49075.2019.9019
  7. S. Hu et al,. "A comparative study of a deep trench superjunction SiC VDMOS device," Journal of Computational Electronics, Vol.18, no.2, pp. 553-560, 2019. DOI: 10.1007/s10825-019-01318-2
  8. B. J. Baliga, "Power semiconductor device figure of merit for high-frequency applications," IEEE Trans. Electron Devices, Vol.64, no.3, pp.674-691, 2017. DOI: 10.1109/TED.2017.2653239
  9. Y. Kobayashi, S. Harada, H. Ishimori, S. Takasu, T. Kojima, K. Ariyoshi, M. Sometani, J. Senzaki, M. Takei, Y. Tanaka and H. Okumura, "3.3kV-class 4H-SiC UMOSFET by Double-trench with Tilt Angle Ion Implantation," Material Science Forum, Vol. 858, pp.974-977, 2016. DOI: 10.4028/www.scientific.net/MSF.858.974
  10. B. J. Baliga, "Silicon Carbide Power Devices," NCSU, USA: World Scientific, pp.259-304, 2006.
  11. N. Iwamura, "SiC power device design and fabrication," Wide Bandgap Semiconductor Power Devices, pp.104-106, 2019.