High-voltage trench-gate hole-gas enhancement-mode HEMT with multi-conduction channels


In this paper, we present a novel high-voltage low on-resistance trench-gate (TG) hole-gas enhancement-mode (E-mode) high-electron mobility transistor (HEMT) with multi-conduction channels (MCs) and investigate its mechanism using simulations. This device features a repetitive AlN/GaN heterojunction unit and a GaN/Al0.26Ga0.74N hetero-junction. Its source and drain are located on the same side of the metal-insulator-semiconductor (MIS) TG, and the source is located beside the gate. During operation, first, 2-D electron gas (2DEG) forms MCs at multiple AlN/GaN hetero-interfaces. These MCs result in ultra-low specific on-resistance (R on,sp) and improved transconductance (g m). Second, 2-D hole gas (2DHG) is induced at the GaN/Al0.26Ga0.74N hetero-interface to prevent electrons from being injected from the source to the MCs. As such, E-mode operation is realized, which exceeds the performance of the conventional E-mode method by depleting the 2DEG under the gate. Third, in the off-state, 2DHG and 2DEG are depleted into negative and positive charges, respectively, thereby forming the polarization junction. This depletion region is extended due to the electric field (E-field) modulation effect by the polarization junction, thereby achieving an enhanced breakdown voltage (BV). Fourth, the drain-induced barrier lowering (DIBL) effect is significantly suppressed, which ensures a high BV and low leakage current. Additionally, due to the unique source location, the TG-MC-HEMT is smaller than the conventional MIS AlGaN/GaN HEMT (Con-HEMT). The BV of the TG-MC-HEMT is 604 V and the R on,sp value can be as small as 0.38 mΩ·cm2.

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This work was supported in part by National Natural Science Foundation of China (Grant No. 51677021) and Fundamental Research Funds for the Central Universities (Grant No. ZYGX2014Z006).

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Correspondence to Xiaorong Luo.

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Yang, C., Luo, X., Deng, S. et al. High-voltage trench-gate hole-gas enhancement-mode HEMT with multi-conduction channels. Sci. China Inf. Sci. 61, 062402 (2018). https://doi.org/10.1007/s11432-017-9198-1

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  • multi-conduction channels
  • 2-D hole gas
  • polarization-junction
  • high-voltage
  • low specific onresistance
  • drain-induced barrier lowering effect