Effects of barrier height fluctuations and electron tunneling on the reverse characteristics of 6H–SiC Schottky contacts

Abstract

Correlation between morphological defects, electron beam-induced current imaging, and the electrical properties of 4H-SiC Schottky diodes J. Appl. Phys. 97, 013540 (2005); 10.1063/1.1829784 X-ray photoelectron spectroscopy study of the heating effects on Pd/6H-SiC Schottky structure Analytic calculations of electron transport across a Schottky barrier in 6H-silicon carbide are presented. The treatment includes the effect of barrier height fluctuations and image charge lowering on both the thermionic emission and electron tunneling processes. The results show that barrier height inhomogeneities are very important, and can lead to reverse current densities that are orders of magnitude higher than obtained from a simple theory. Formation of detrimental filamentary currents are predicted. The results are in very good agreement with published experimental data at 300 K. Finally, under forward biasing conditions, the analytical theory yields ideality factors of 1.037 in close agreement with measurements.

Combined thermionic emission and tunneling mechanisms for the analysis of the leakage current for Ga2O3 Schottky barrier diodes

“…As shown in Fig. 1, the U(x) is the potential energy profile, for an arbitrary Schottky diode as measured with respect to the energy of the bottom of the conduction band in the bulk of the semiconductor, and it can be given by [27,34]:…”

“…Here the component of reverse tunneling current density J Tun can be expressed as [27,[31][32][33][34] and the component of TE current density J Therm can be expressed as [27] For the energies E x > U max that correspond to the TE mechanism, the tunneling probability is equal to unity. Including the barrier lowering model and approximating the Fermi-Dirac statistics with the Maxwell-Boltzmann, Eq.…”

Establishing the cause of poor device quality in Schottky barrier diodes fabricated on bulk n ‐type 6H‐SiC

“…f) Rough approximation based on Padovani [20] using Vbi = 1.4 eV and assuming xc ≈ 10 Å. g) Rough approximation based on Padovani [20] using d ≈ 5 Å and assuming zero bias conditions. h) Shown by Zheng et al [21] to be very important under low bias conditions. i) Powell et al [22].…”

Reverse bias-dependence of schottky barrier height on silicon carbide: influence of the temperature and donor concentration

“…However, due to the high electric fields normally encountered in SiC devices, the reverse leakage current of Schottky diodes can be significantly enhanced prior to junction breakdown due to the tunneling mechanism [3]. The high electric fields encountered in SiC and other wide band gap materials lead to significant tunneling through the Schottky barrier thus increasing the leakage current by many orders of magnitude over that predicted by simple thermionic emission (TE) calculations [3][4][5][6][7][8][9][10]. However, the tunneling leakage current, which calculated with the extracted SBH from forward I-V data, is discrepancy of the experimental data [3], [4], [9].…”