Abstract—We propose a vertical high-permittivity trench power metal oxide semiconductor (HKTMOS) device with an alternating N&P drift regions and high-permittivity (HK) trench sandwiched in between. The unique structure guarantees uniform potential distribution for a wide voltage range at the blocking state owing to both the HK potential modulation effect and the superjunction (SJ) charge balance. The specific on-resistance (Rons) of HKTMOS is orders of magnitude lower than the SJ counterparts in the on-state because of the strong accumulation effect brought by the HK trenches. Although the gate charges also significantly rise because of the accumulation, the figures of merit (FOM) of HKTMOS still decrease considerably compared to the SJ under the same device length condition. An expression for the FOM is derived, demonstrating that the FOM of HKTMOS is proportional to the square of the HK trench depth, which agrees with the simulation results well. The simulation indicates that within the BV range of 500~2000 V, the Rons of HKTMOS is 1~2 orders of magnitude lower than that of SJ, and its FOM is 17.4%~44.1% that of SJ under the same device size condition. Furthermore, HKTMOS also demonstrates better charge imbalance tolerance than SJ.
Index Terms—High permittivity, figures of merit, specific on resistance, power MOS.
The authors are with the State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China (e-mail: Jefferyli@uestc.edu.cn).
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Cite:Junhong Li and Kun Xiao, "Investigation of a Novel High-Permittivity Trench MOS Device with Small Figures of Merit," International Journal of Computer Theory and Engineering vol. 10, no. 1, pp. 30-37, 2018.
