Abstract
Oxide dielectric present in metal oxide semiconductor high electron mobility transistor plays an important role during formation of two dimensional electron gas (2DEG). The sheet charge concentration \((\hbox {n}_{{\mathrm{s}}})\) is dependent on the Eigenenergy states present in triangular quantum well at AlGaN/GaN interface. The energy states are in fact functions of vertical electric field at the edge of the well. Therefore in this paper a model is developed to find out Electric field and flat-band voltage \((\hbox {V}_{{\mathrm{T}}})\) by adopting energy band approach to incorporate oxide parameters in it unlike the conventional method of solving Poisson’s equation, which is the uniqueness of this paper. The Eigenenergy states are dependent non-linearly on electric field. In the present case, three quantum states in the well are considered along with the Fermi–Dirac distribution function to obtain \(\hbox {n}_{\mathrm{s}}\). The dependence of 2DEG density, electric field and flat-band voltage on the oxide parameters such as thickness and electrical permittivity is analyzed. With respect to thickness in \(\hbox {SiO}_{2}\) and \(\hbox {Al}_{2}\hbox {O}_{3},\, \hbox {n}_{\mathrm{s}}\) shows inverse relationship; whereas in \(\hbox {HfO}_{2}\) it is direct due to positive charges accumulated at oxide/barrier interface. To the best of author’s knowledge the work is first of its kind and due to lack of experimental data; the obtained results are compared with TCAD results to validate the model.
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Huang, S., Wei, K., Liu, G., Zheng, Y., Wang, X., Pang, L., Kong, X., Liu, X., Tang, Z., Yang, S., Jiang, Q., Chen, K.J.: High- f\(_{{\rm MAX}}\) High Johnson’s figure-of-merit \(0.2-\mu \)m gate AlGaN/GaN HEMTs on silicon substrate with AlN/SiN\(_{{\rm x}}\) passivation. IEEE Electron Device Lett. 35, 315–317 (2014)
Narita, T., Fujimoto, Y., Wakejima, A., Egawa, T.: Identification of local gate leakage with electroluminescence using AlGaN/GaN HEMTs. Electron. Lett. 50, 1162–1164 (2014)
Husna, F., Lachab, M., Sultana, M., Adivarahan, V., Fareed, Q., Khan, A.: High-temperature performance of AlGaN/GaN MOSHEMT with SiO\(_{2}\) gate insulator fabricated on Si (111) substrate. IEEE Trans. Electron Devices 59, 2424–2429 (2012)
Basu, S., Singh, P., Lin, S., Sze, P., Wang, Y.: Effects of short-term DC-bias-induced stress on n-GaN/AlGaN/ GaN MOSHEMTs with liquid-phase-deposited Al\(_2\)O\(_{3}\) as a gate dielectric. IEEE Trans. Electron Devices 57, 2978–2987 (2010)
Wu, T., Lin, S., Sze, P., Huang, J., Chien, W., Hu, C., Tsai, M., Wang, Y.: AlGaN/GaN MOSHEMTs with liquid-phase-deposited TiO\(_{2}\) as gate dielectric. IEEE Trans. Electron Devices 56, 2911–2916 (2009)
Tapajna, M., Kuzmík, J.: A comprehensive analytical model for threshold voltage calculation in GaN based metal-oxide-semiconductor high-electron-mobility transistors. Appl. Phys. Lett. 100, 1135091–1135094 (2012)
Lenka, T.R., Panda, A.K.: Characteristics study of 2DEG transport properties of AlGaN/GaN and AlGaAs/GaAs-based HEMT. Semiconductors 45, 660–665 (2011)
Delagebeaudeuf, D., Linh, N.T.: Metal-(n) AIGaAs-GaAs two-dimensional electron gas FET. IEEE Trans. Electron Devices 29, 955–960 (1982)
Ng, S., Khoie, R., Venkat, R.: A two-dimensional self-consistent numerical model for high electron mobility transistor. IEEE Trans. Electron Devices 38, 852–861 (1991)
Stengel, F., Noor Mohammad, S., Morkoc, H.: Theoretical investigation of electrical characteristics of AlGaN/GaN modulation doped field-effect transistors. J. Appl. Phys. 80, 3031–3042 (1996)
Ambacher, O., et al.: Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N and Ga-face AlGaN/GaN hetero structures. J. Appl. Phys. 85, 3222–3233 (1999)
Rashmi, A.K., Haldar, S., Gupta, R.S.: An accurate charge control model for spontaneous and piezoelectric polarization dependent two-dimensional electron gas sheet charge density of lattice-mismatched AlGaN/GaN HEMTs. Solid State Electron. 46, 621–630 (2002)
Pandey, D., Lenka, T.R.: Model development for analyzing 2DEG sheet charge density and threshold voltage considering interface DOS for AlInN/GaN MOSHEMT. J. Semicond. 35, 1040011–1040014 (2014)
Hayashi, Y., Sugiura, S., Kishimoto, S., Mizutani, T.: AlGaN/GaN MOSHFETs with HfO\(_{2}\) gate oxide: a simulation study. Solid State Electron. 54, 1367–1371 (2010)
Tsividis, Y.: Operation and Modeling of The MOS Transistor, 2nd edn. Oxford University Press, Oxford (2010)
Li, S.S.: Semiconductor Physical Electronics, 1st edn. Plenum Press, New York (1993)
Kola, S., Golio, J.M., Maracas, G.N.: An analytical expression for Fermi level versus sheet carrier concentration for HEMT modeling. IEEE Electron Device Lett. 9, 136–138 (1988)
Bougrov, V., Levinshtein, M., Rumyantsev, S., Zubrilov, A.: “Gallium nitride,” in Properties of Advanced Semiconductor Materials GaN. AlN, InN, BN, SiC, SiGe, pp. 1–30. Wiley, New York (2001)
Yue, Y., Hao, Y., Zhang, J., Ni, J., Mao, W., Feng, Q., Liu, L.: AlGaN/GaN MOS-HEMT with HfO\(_{2}\) dielectric and Al\(_{2}\)O\(_{3}\) interfacial passivation layer grown by atomic layer deposition. IEEE Electron Device Lett. 29, 838–840 (2008)
Segev, D., Van de Walle, C.G.: Origins of Fermi-level pinning on GaN and InN polar and nonpolar surfaces. Europhys. Lett. 76, 305–311 (2006)
Kirkpatrick, C.J., et al.: Atomic layer deposition of SiO\(_{2}\) for AlGaN/GaN MOS-HFETs. Electron Device Letter 33, 1240–1242 (2012)
Tapajna, M., Kuzmík, J.: Control of threshold voltage in GaN based metal-oxide-semiconductor high-electron mobility transistors towards the normally-off operation. Jpn. J. Appl. Phys. 52, 08JN081-5 (2013)
SILVACO. International Incorporated, ATLAS User’s Manual, Version 5.12.0.R. USA, Silvaco inc., (2010)
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The authors acknowledge the Microelectronics Computational Lab in Department of Electronics & Communication Engineering of National Institute of Technology Silchar, India for providing all necessary facilities to carry out the research work.
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Swain, R., Panda, J., Jena, K. et al. Modeling and simulation of oxide dependent 2DEG sheet charge density in AlGaN/GaN MOSHEMT. J Comput Electron 14, 754–761 (2015). https://doi.org/10.1007/s10825-015-0711-3
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DOI: https://doi.org/10.1007/s10825-015-0711-3