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The mobility of two-dimensional electron gas in AlGaN/GaN heterostructures with varied Al content

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Abstract

The mobility of the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures changes significantly with Al content in the AlGaN barrier layer, while few mechanism analyses focus on it. Theoretical calculation and analysis of the 2DEG mobility in AlGaN/GaN heterostructures with varied Al content are carried out based on the recently reported experimental data. The 2DEG mobility is modeled analytically as the total effects of the scattering mechanisms including acoustic deformation-potential, piezoelectric, polar optic phonon, alloy disorder, interface roughness, dislocation and remote modulation doping scattering. We show that the increase of the 2DEG density, caused by the ascension of the Al content in the barrier layer, is a dominant factor that leads to the changes of the individual scattering processes. The change of the 2DEG mobility with Al content are mainly determined by the interface roughness scattering and the alloy disorder scattering at 77 K, and the polar optic phonon scattering and the interface roughness scattering at the room temperature. The calculated function of the interface roughness parameters on the Al content shows that the stress caused AlGaN/GaN interface degradation at higher Al content is an important factor in the limitation of the interface roughness scattering on the 2DEG mobility in AlGaN/GaN heterostructures with high Al content.

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References

  1. Smorchkova I P, Elsass C R, Ibbetson J P, et al. Polarization-induced charge and electron mobility in AlGaN/GaN heterostructures grown by plasma-assisted molecular-beam epitaxy. J Appl Phys, 1999, 86: 4520–4526

    Article  Google Scholar 

  2. Ambacher O, Smart J, Shealy J R, et al. Two-dimensional gases induced by spontaneous and piezoelectric polarization charges in N-and Ga-face AlGaN/GaN heterostructures. J Appl Phys, 1999, 85: 3222–3233

    Article  Google Scholar 

  3. Ambacher O, Foutz B, Smart J, et al. Two dimensional electron gases induced by spontaneous and piezoelectric polarization in undoped and doped AlGaN/GaN heterostructures. J Appl Phys, 2000, 87: 334–344

    Article  Google Scholar 

  4. Keller S, Parish G, Fini P T, et al. Metalorganic chemical vapor deposition of high mobility AlGaN/GaN heterostructures. J Appl Phys, 1999, 86: 5850–5857

    Article  Google Scholar 

  5. Wu Y-F, Keller B P, Fini P, et al. High Al-content AlGaN/GaN MODFET’s for ultrahigh performance. IEEE Elect Dev Lett, 1998, 19: 50–53

    Article  Google Scholar 

  6. Arulkumaran S, Egawa T, Ishikawa H, et al. Characterization of different-Al-content AlxGal-xN/GaN heterostructures and high-electron-mobility transistors on sapphire. J Vac Sci Tech B, 2003, 21: 888–894

    Article  Google Scholar 

  7. Miyoshi M, Sakai M, Ishikawa H, et al. MOVPE growth and characterization of high-Al-content AlGaN/GaN heterostructures on 100-mm-diameter sapphire substrates. J Cryst Growth, 2004, 272: 293–299

    Article  Google Scholar 

  8. Miyoshi M, Egawa T, Ishikawa H. Structural characterization of strained AlGaN layers in different Al content AlGaN/GaN heterostructures and its effect on two-dimensional electron transport properties. J Vac Sci Tech B, 2005, 23: 1527–1531

    Article  Google Scholar 

  9. Fang F F, Howard W E. Negative field-effect mobility on (100) Si surfaces. Phys Rev Lett, 1966, 16: 797–799

    Article  Google Scholar 

  10. Davies J H. The Physics of Low Dimensional Semiconductor. Cambridge UK: Cambridge University Press, 1998

    Google Scholar 

  11. Zanato D, Gokden S, Balkan N, et al. The effect of interface-roughness and dislocation scattering on low temperature mobility of 2D electron gas in GaN/AlGaN. Semicond Sci Tech, 2004, 19: 427–432

    Article  Google Scholar 

  12. Gelmont B L, Shur M, Stroscio M. Polar optical-phonon scattering in three-and two-dimensional electron gases. J Appl Phys, 1995, 77: 657–660

    Article  Google Scholar 

  13. Bastard G. Energy levels and alloy scattering in InP-In(Ga)As heterojunctions. Appl Phys Lett, 1983, 43: 591–593

    Article  Google Scholar 

  14. Ferry D K, Goodnick S M. Transport in Nanostructures. Cambridge UK: Cambridge University Press, 1999

    Google Scholar 

  15. Jena D, Gossard A C, Mishra U K. Dislocation scattering in a two-dimensional electron gas. Appl Phys Lett, 2000, 76: 1707–1709

    Article  Google Scholar 

  16. Levinshtein M E, Rumyantsev S L, Shur M S. Properties of advanced semiconductor materials GaN, AlN, InN, BN, SiC, SiGe. New York: John Wiley & Sons, 2001

    Google Scholar 

  17. Knap W, Contreras S, Alause H, et al. Cyclotron resonance and quantum Hall effect studies of the two-dimensional electron gas confined at the GaN/AlGaN interface. Appl Phys Lett, 1997, 70: 2123–2125

    Article  Google Scholar 

  18. Jena D. Polarization induced electron populations in III–V nitride semiconductors: Transport, growth, and device applications. phD thesis. Santa Barbara USA: University of California, Santa Barbara, 2003

    Google Scholar 

  19. Leung K, Wright A F, Stechel E B. Charge accumulation at a threading edge dislocation in gallium nitride. Appl Phys Lett, 1999, 74: 2495–2497

    Article  Google Scholar 

  20. Wang T, Ohno Y, Lachab M, et al. Electron mobility exceeding 104 cm2/Vs in an AlGaN-GaN heterostructure grown on a sapphire substrate. Appl Phys Lett, 1999, 74: 3531–3533

    Article  Google Scholar 

  21. Zhang Y F, Smorchkova Y, Elsass C, et al. Polarization effects and transport in AlGaN/GaN system. J Vac Sci Tech B, 2000, 18: 2322–2327

    Article  Google Scholar 

  22. Jena D, Smorchkova I P, Gossard A C, et al. Electron transport in III–V nitride two-dimensional electron gases. Phys Stat Sol (b), 2001, 228: 617–619

    Article  Google Scholar 

  23. Oberhuber R, Zandler G, Vogl P. Mobility of two-dimensional electrons in AlGaN/GaN modulation-doped field-effect transistors. Appl Phys Lett, 1998, 73: 818–820

    Article  Google Scholar 

  24. Tang N. Transport properties of the two-dimensional electron gas in AlxGal-xN/GaN heterostructures. phD thesis. Beijing: Peking University, 2007

    Google Scholar 

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Correspondence to JinFeng Zhang.

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Supported by the Key Program of the National Natural Science Foundation of China (Grant No. 60736033), and Xi’an Applied Materials Innovation Fund (Grant No. XA-AM-200703), and the Open Fund of Key Laboratory of Wide Bandgap Semiconductors Material and Devices, Ministry of Education, China

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Zhang, J., Hao, Y., Zhang, J. et al. The mobility of two-dimensional electron gas in AlGaN/GaN heterostructures with varied Al content. Sci. China Ser. F-Inf. Sci. 51, 780–789 (2008). https://doi.org/10.1007/s11432-008-0056-7

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  • DOI: https://doi.org/10.1007/s11432-008-0056-7

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