Efficient Acceptor Activation in AlxGa1−xN/GaN Doped Superlattices

Abstract

Mg-doped superlattices consisting of uniformly doped AlxGa1−xN and GaN layers are analyzed by Hall-effect measurements. Acceptor activation energies of 70 meV and 58 meV are obtained for superlattice structures with an Al mole fraction ofx = 0.10 and 0.20 in the barrier layers, respectively. These energies are significantly lower than the activation energy measured for Mg-doped GaN thin films. At room temperature, the doped superlattices have free hole concentrations of 2 × 1018 cm−3 and 4 × 1018 cm−3 forx = 0.10 and 0.20, respectively. The increase in hole concentration with Al content of the superlattice is consistent with theory. The room temperature conductivity measured for the superlattice structures are 0.27 S/cm and 0.64 S/cm for an Al mole fraction ofx = 0.10 and 0.20, respectively.

This is a preview of subscription content, access via your institution.

References

  1. 1

    S. Strite and H. Morkoc, GaN, AlN, and InN: A review, Journal of Vacuum Technology B10(4), 1237 (1992)

    Article  Google Scholar 

  2. 2

    H. Nakayama, P. Hacke, M.R.H. Khan, T. Detchprohm, K. Hiramatsu, and N. Sawaki, Electrical transport properties of p-GaN, Japanese Journal of Applied Physics 35, L282 (1996)

    CAS  Article  Google Scholar 

  3. 3

    S. Fischer, C. Wetzel, E. E. Haller, and B. K. Meyer, On p-type doping in GaN -acceptor binding energies, Applied Physics Letters 67, 1298 (1995)

    CAS  Article  Google Scholar 

  4. 4

    C. Ronning, E. P. Carlson, D. B. Thomson, and R. F. Davis, Optical activation of Be implanted into GaN, Applied Physics Letters 73, 1622 (1998)

    CAS  Article  Google Scholar 

  5. 5

    J. W. Lee, S. J. Pearton, J. C. Zolper, R. A. Stall, Hydrogen passivation of Ca acceptors in GaN, Applied Physics Letters 68, 2102 (1996)

    CAS  Article  Google Scholar 

  6. 6

    E. F. Schubert, W. Grieshaber, and I. D. Goepfert, Enhancement of deep acceptor activation in semiconductors by superlattice doping, Applied Physics Letters 69, 3737 (1996)

    CAS  Article  Google Scholar 

  7. 7

    M. Katsuragawa, S. Sota, M. Komori, C. Anbe, T. Takeuchi, H. Sakai, H. Amano, I. Akasaki, Thermal ionization energy of Si and Mg in AlGaN, Journal of Crystal Growth 189/190, 528 (1998)

    CAS  Article  Google Scholar 

  8. 8

    T. Tanaka, A. Watanabe, H. Amano, Y. Kobayasi, I. Akasaki, S. Yamazaki, and M. Koike, p-type conduction in Mg-doped GaN and Al0.08GaN0.92N grown by metalorganic vapor phase epitaxy, Applied Physics Letters 65, 593 (1994)

    CAS  Article  Google Scholar 

  9. 9

    A. Saxler, W. C. Mitchel, P. Kung, and M. Razeghi, Aluminum gallium nitride shortperiod superlattces doped with magnesium, Applied Physics Letters 74, 2023 (1999)

    CAS  Article  Google Scholar 

  10. 10

    We use εr = 9.0 and εr = 8.5 for the relative dielectric constant for GaN and AlN, respectively. These values are compiled in Reference 1.

  11. 11

    The experimental effective hole mass in AlxGa1.xN is unknown at this time. Although, Katsuragawa et al. in Reference 7 reported no significant change in the activation energy of Mg in AlxGa1.xN indicating no significant change in the hole mass. See, for instance, Gil, Group III Nitride Semiconductor Compounds (Clarendon Press, Oxford, 1998)

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to I. D. Goepfert.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Goepfert, I.D., Schubert, E.F., Osinsky, A. et al. Efficient Acceptor Activation in AlxGa1−xN/GaN Doped Superlattices. MRS Online Proceedings Library 595, 385 (1999). https://doi.org/10.1557/PROC-595-F99W3.85

Download citation