Design and Fabrication of Non-Uniform Spacing Multiple Floating Field Limiting Rings for 6500V 4H-SiC JBS Diodes

Abstract:

Designed for 6500V 4H-SiC JBS diodes, a highly-efficient termination structure of a non-uniform multiple floating field limiting rings (MFFLR) featuring with a non-uniform ring spacing and a multiple region division is studied and purposed. For each region, ring spacing is modulated independently by a multiplication factor and a linear increment factor. The non-uniform MFFLR structure is simulated and optimized for a better electric field distribution and a higher breakdown voltage. Based on the simulation results, 4H-SiC JBS diodes with the optimized non-uniform termination designs are fabricated. Experimental results show that the SiC JBS diode with optimized non-uniform MFFLR termination structure can achieve a breakdown voltage of up to 7800 V, and its termination efficiency is about 94% of an ideal parallel-plane junction’s. Our results demonstrate that the optimized non-uniform MFFLR termination structure is capable for SiC JBS diodes with breakdown voltage of 6500V and above. Our results can provide a valuable design methodology of edge termination structures for other high-voltage SiC devices.

• Periodical: Materials Science Forum (Volume 1014)
• Pages: 120-125
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1014.120
• Online since: November 2020
• Authors: Ling Sang*, Li Xin Tian, Fei Yang, Jing Hua Xia, Rui Jin, Yi Ying Zha, Liang Tian, Xi Ping Niu, Jun Min Wu
• Keywords: 4H-SiC, Diode, Field Limiting Rings, JBS, Non-Uniform

References

[1] M. Bhatnagar and B. J. Baliga, Comparison of 6H-SiC, 3C-SiC, and Si for power devices, IEEE Trans. Electron Devices 40 (1993) 645-655.

DOI: 10.1109/16.199372

[2] H. Matsunami and T. Kimoto, Step-controlled epitaxial growth of SiC:High quality homoepitaxy, Mater. Sci. Eng. R20 (1997) 125-166.

DOI: 10.1016/s0927-796x(97)00005-3

[3] V.A.K. Temple, M.S. Adler, Calculation of the diffusion curvature related avalanche breakdown in high voltage planar p-n junctions, IEEE Trans 22 (1975) 910-916.

DOI: 10.1109/t-ed.1975.18241

[4] Q. Song, Y. Zhang, Y.Zhang, X. Tang, Simulation study on 4H-SiC power devices with high-k dielectric FP termination, Diam Relat Mater 22 (2012) 42-47.

DOI: 10.1016/j.diamond.2011.12.010

[5] R. Huang, Y. Tao, P. Cao, L. Wang, G. Chen, S. Bai, Development of 10 kV 4H-SiC JBS diode with FGR termination, J Semicond 35 (2014) 074005-1-074005-4.

DOI: 10.1088/1674-4926/35/7/074005

[6] W. Sung, A.Q. Huang, B.J. Baliga, Bevel junction termination extension (bevel-JTE) - a new edge termination technique for 4H-SiC high-voltage device, IEEE Electron Device Lett 36 (2015) 594-596.

DOI: 10.1109/led.2015.2427654

[7] I.H. Kang, J.Y. Song, S.J. Joo, W.Bahng, S.C. Kim, N.K. Kim, Effect of the doping concentration and space of both p-grid and field limiting ring on 4H-SiC Junction Barrier Schottky diode with single ion implantation process, Materials Science Forum 600-603 (2009) 959-962.

DOI: 10.4028/www.scientific.net/msf.600-603.959

[8] D.C. Sheridan, G.Niu, J.N. Merrett, J.D. Cressler, C.Ellis, C.C. Tin, Design and fabrication of planar guard ring termination for high-voltage SiC diodes, Solid-State Electronics 44 (2000) 1367-1372.

DOI: 10.1016/s0038-1101(00)00081-2

[9] V. Soler, M. Berthou, A.Mihaila, J.Montserrat, P.Godignon, J.Rebollo, J.Millan, Experimental analysis of planar edge terminations for high voltage 4H-SiC devices, 2015 45th European Solid State Device Research Conference (ESSDERC), Graz, 2015, pp.68-71.

DOI: 10.1109/essderc.2015.7324715

[10] H.Yuan, Q.Song, X.Tang, Y.Zhang, Y.Zhang, Y.Zhang, Design and experiment of 4H-SiC JBS diodes achieving a near-theoretical breakdown voltage with non-uniform floating limiting rings terminal, Solid-State Electronics 123 (2016) 58-62.

DOI: 10.1016/j.sse.2016.05.014