Enhanced-Mode NiO/Beta-Ga2O3 Heterojunction Field-Effect Transistor: A TCAD Study
DOI:
https://doi.org/10.54644/jte.2025.1665Abstract
Ga2O3 is considered to be a promising candidate for the fabrication of high-power semiconductor devices because it has the wide range of band gap from 3.0 eV to 4.9 eV. Because the lack of p-type Ga2O3, p-type NiO/n-type Ga2O3 MOSFETs is expected to realize Ga2O3 power MOSFETs in industry because both Ga2O3 and NiO have wide band gap and high critical electric field. In this work, p-type NiO/n-type Ga2O3 MOSFETs were investigated under the effects of gate-drain distance LGD and acceptor concentration NA in NiO layer, using TCAD simulations. It was found that drain current increases 3 times as the LGD decreases in a range from 8 µm to 1 µm. NA of NiO layer strongly affects the threshold voltage Vth of the devices, illustrating the positive shift of Vth as NA increased from 1.0×1016 cm-3 to 1.0×1020 cm-3. The NiO/Ga2O3 MOSFETs operates in E-mode with Vth > 0 when NA ³ 1.0×1018 cm-3. The change in NA leads to the transformation of NiO/Ga2O3 junction, from a linear-junction (NA = 1.0×1016 cm-3) to an abrupt-junction (NA = 1.0×1020 cm-3). The rise in Schottky barrier within the depletion region at NiO/Ga2O3 junction creates the E-mode of the p-type NiO/n-type Ga2O3 MOSFETs.
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References
[1] H. von Wenckstern, "Group-III Sesquioxides: Growth, Physical Properties and Devices," Advanced Electronic Materials, vol. 3, p. 1600350, 2017.
[2] S. J. Pearton et al., "A review of Ga2O3 materials, processing, and devices," Applied Physics Reviews, vol. 5, 2018.
[3] J. Yang et al., "Vertical geometry 33.2 A, 4.8 MW cm2 Ga2O3 field-plated Schottky rectifier arrays," Applied Physics Letters, vol. 114, 2019.
[4] Z. Galazka et al., "Scaling-Up of Bulk β-Ga2O3 Single Crystals by the Czochralski Method," ECS Journal of Solid State Science and Technology, vol. 6, p. Q3007, 2017.
[5] A. Kuramata, K. Koshi, S. Watanabe, Y. Yamaoka, T. Masui, and S. Yamakoshi, "High-quality β-Ga2O3 single crystals grown by edge-defined film-fed growth," Japanese Journal of Applied Physics, vol. 55, p. 1202A2, 2016.
[6] F. Alema, Y. Zhang, A. Osinsky, N. Valente, A. Mauze, T. Itoh, and J. S. Speck, "Low temperature electron mobility exceeding 104 cm2/V s in MOCVD grown β-Ga2O3," APL Materials, vol. 7, 2019.
[7] K. Sasaki, M. Higashiwaki, A. Kuramata, T. Masui, and S. Yamakoshi, "MBE grown Ga2O3 and its power device applications," Journal of Crystal Growth, vol. 378, pp. 591-595, 2013.
[8] H. Murakami et al., "Homoepitaxial growth of β-Ga2O3 layers by halide vapor phase epitaxy," Applied Physics Express, vol. 8, p. 015503, 2014.
[9] A. Bhattacharyya et al., "Multi-kV class β-Ga₂O₃ MESFETs with a lateral figure of merit up to 355 MW/cm²," IEEE Electron Device Letters, vol. 42, pp. 1272-1275, 2021.
[10] C. Wang et al., "Demonstration of the p-NiO x/n-Ga 2 O 3 heterojunction gate FETs and diodes with BV 2/R on, sp figures of merit of 0.39 GW/cm 2 and 1.38 GW/cm 2," IEEE Electron Device Letters, vol. 42, pp. 485-488, 2021.
[11] X. Zhou et al., "Realizing high-performance β-Ga₂O₃ MOSFET by using variation of lateral doping: a TCAD study," IEEE Transactions on Electron Devices, vol. 68, pp. 1501-1506, 2021.
[12] H. C. Huang et al., "β-Ga2O3 FinFETs with ultra-low hysteresis by plasma-free metal-assisted chemical etching," Applied Physics Letters, vol. 121, 2022.
[13] Z. Feng et al., "Design and fabrication of field-plated normally off β-Ga2O3 MOSFET with laminated-ferroelectric charge storage gate for high power application," Applied Physics Letters, vol. 116, 2020.
[14] H. Yuan et al., "Contact barriers modulation of graphene/β-Ga2O3 interface for high-performance Ga2O3 devices," Applied Surface Science, vol. 527, p. 146740, 2020.
[15] H. B. Do, A. V. Phan-Gia, V. Q. Nguyen, and M. M. De Souza, "Optimization of normally-off β-Ga2O3 MOSFET with high Ion and BFOM: A TCAD study," AIP Advances, vol. 12, 2022.
[16] D. Wakimoto, C. H. Lin, Q. T. Thieu, H. Miyamoto, K. Sasaki, and A. Kuramata, "Nitrogen-doped β-Ga2O3 vertical transistors with a threshold voltage of≥ 1.3 V and a channel mobility of 100 cm2 V− 1 s− 1," Applied Physics Express, vol. 16, p. 036503, 2023.
[17] Y. Lv et al., "Oxygen annealing impact on β-Ga2O3 MOSFETs: Improved pinch-off characteristic and output power density," Applied Physics Letters, vol. 117, 2020.
[18] X. Lu, Y. Deng, Y. Pei, Z. Chen, and G. Wang, "Recent advances in NiO/Ga2O3 heterojunctions for power electronics," Journal of Semiconductors, vol. 44, p. 061802, 2023.
[19] A. A. Ahmed, M. Devarajan, and N. Afzal, "Growth of rf sputtered nio films on different substrates—a comparative study," Surface Review and Letters, vol. 24, p. 1750096, 2017.
[20] Y. Wang et al., "Demonstration of β-Ga₂O₃ Superjunction-Equivalent MOSFETs," IEEE Transactions on Electron Devices, vol. 69, pp. 2203-2209, 2022.
[21] J. S. Li et al., "1 mm2, 3.6 kV, 4.8 A NiO/Ga2O3 Heterojunction Rectifiers," ECS Journal of Solid State Science and Technology, vol. 12, p. 085001, 2023.
[22] Y. Qin et al., "10-kV Ga 2 O 3 Charge-Balance Schottky Rectifier Operational at 200° C," IEEE Electron Device Letters, vol. 44, pp. 1268-1271, 2023.
[23] A. K. Bhat, H. S. Kim, A. Mishra, M. D. Smith, M. J. Uren, and M. Kuball, "Analysis of interface trap induced ledge in β-Ga2O3 based MOS structures using UV-assisted capacitance–voltage measurements," Journal of Applied Physics, vol. 135, 2024.
[24] A. Almalki et al., "Investigation of deep defects and their effects on the properties of NiO/β-Ga2O3 heterojuncion diodes," Materials Today Electronics, vol. 4, p. 100042, 2023.
[25] H. Gong, X. Chen, Y. Xu, F. F. Ren, S. Gu, and J. Ye, "A 1.86-kV double-layered NiO/β-Ga2O3 vertical p–n heterojunction diode," Applied Physics Letters, vol. 117, 2020.
