Abstract
Electrical properties, including current-voltage (I-V) and capacitance-voltage (C-V) characteristics, have been measured on a large number of Ti, Ni, and Pt-based Schottky barrier diodes on 4H-SiC epilayers. Various nonideal behaviors are frequently observed, including ideality factors greater than one, anomalously low I-V barrier heights, and excess leakage currents at low forward bias and in reverse bias. The nonidealities are highly nonuniform across individual wafers and from wafer to wafer. We find a pronounced linear correlation between I-V barrier height and ideality factor for each metal, while C-V barrier heights remain constant. Electron beam induced current (EBIC) imaging strongly suggests that the nonidealities result from localized low barrier height patches. These patches are related to discrete crystal defects, which become visible as recombination centers in the EBIC images. Alternative explanations involving generation-recombination current, uniform interfacial layers, and effects related to the periphery are ruled out.
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W.J. Schaffer, G.H. Negley, K.G. Irvine, and J.W. Palmour, Diamond, SiC, and Nitride Wide Bandgap Semiconductors, ed. C.H. Carter Jr., G. Gildenblatt, S. Nakamura, and R.J. Nemanich (Pittsburgh, PA: MRS, 1994), p. 595.
C.E. Weitzel, J.W. Palmour, C.H. Carter Jr., K. Moore, K.J. Nordquist, S. Allen, C. Thero, and M. Bhatnagar, IEEE Trans. Electron Devices 43, 1732 (1996).
M. Bhatnagar, B.J. Baliga, H.R. Kirk, and G.A. Rozgonyi, IEEE Trans. Electron Devices 43, 150 (1996).
D. Defives, O. Noblanc, C. Dua, C. Brylinski, M. Barthula, V. Aubry-Fortuna, and F. Meyer, IEEE Trans. Electron Devices 46, 449 (1999).
P.G. Neudeck and J.A. Powell, IEEE Electron Device Lett. 15, 63 (1994).
P.G. Neudeck, W. Huang, and M. Dudley, Power Semiconductor Materials and Devices, ed. S.J. Pearton, R.J. Shul, E. Wolfgang, F. Ren, and S. Tenconi (Warrendale, PA: MRS, 1998), p. 285.
P.G. Neudeck, W. Huang, and M. Dudley, IEEE Trans. Electron Devices 46, 478 (1999).
T. Kimoto, N. Miyamoto, and H. Matsunami, IEEE Trans. Electron Devices 46, 471 (1999).
E.H. Rhoderick and R.H. Williams, Metal-Semiconductor Contacts (Oxford, U.K.: Clarendon Press, 1988).
R.F. Schmitsdorf, T.U. Kampen, and W. Mönch, J. Vac. Sci. Technol. B 15, 1221 (1997).
L.F. Wagner, R.W. Young, and A. Sugerman, IEEE Electron Device Lett. 4, 320 (1983).
D. Alok, R. Egloff, and E. Arnold, Mater. Sci. Forum 264–268, 929 (1998).
F.A. Padovani and R. Stratton, Solid State Electron. 9, 695 (1966).
C.R. Crowell and V.L. Rideout, Solid State Electron. 12, 89 (1969).
H.C. Card and E.H. Rhoderick, J. Phys. D: Appl. Phys. 4, 1589 (1971).
R.T. Tung, Phys. Rev. B 45, 13509 (1992).
J.R. Sullivan, R.T. Tung, M.R. Pinto, and W.R. Graham, J. Appl. Phys. 70, 7403 (1991).
A.Y.C. Yu and E.H. Snow, J. Appl. Phys. 39, 3008 (1968).
C.-T. Sah, R.N. Noyce, and W. Shockley, Proc. IRE 45, 1228 (1957).
D.B. Holt, SEM Microcharacterization of Semiconductors, ed. D.B. Holt and D.C. Joy (London: Academic, 1989), p. 241.
J.M. Gibson, D.C. Joy, R.T. Tung, J.L. Ellison, C. Pimentel, and A.F.J. Levi, Layered Structures and Epitaxy, ed. J.M. Gibson, G.C. Osbourn, and R.M. Tromp (Pittsburgh, PA: MRS, 1986), p. 163.
W.L. Zhou, P. Pirouz, and J.A. Powell, Mater. Sci. Forum 264–268, 417 (1998).
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Skromme, B.J., Luckowski, E., Moore, K. et al. Electrical characteristics of schottky barriers on 4H-SiC: The effects of barrier height nonuniformity. J. Electron. Mater. 29, 376–383 (2000). https://doi.org/10.1007/s11664-000-0081-9
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DOI: https://doi.org/10.1007/s11664-000-0081-9