Schottky barrier characteristics of Pt contacts to n-type InGaN

Abstract

Schottky barrier behaviors of Pt contacts to n-InGaN have been investigated by means of current-voltage (I-V) and capacitance-voltage (C-V) methods. It is found that the Schottky barrier heights (SBHs) determined by thermionic emission (TE) and thermionic field emission (TFE) modes using the I-V data are quite different from each other. However, the SBHs obtained by the TFE mode are fairly similar to theoretically calculated values, which are in good agreement with the results obtained by the C-V method. It is also shown that the SBHs and the ideality factors calculated by the TE and TFE modes decrease with increasing annealing temperature. The different SBHs obtained by the TE and TFE modes, the annealing temperature dependence of the SBHs, and the ideality factors are described and discussed in terms of the presence of different types of native point defects near the InGaN surface.

Graphene-GaN Schottky diodes

“…It is noted that the obtained n value is much smaller than the previously reported value of 2.4, indicating that the Schottky parameters obtained by the I-V method are much more accurate and reliable than those in previous work [33,34]. However, the obtained n value is larger than unity, which may be attributed to GaN surface states originating from native crystal defects [47,48], interfacial layers [49,50], barrier inhomogeneities [43,44], residual chemical contaminants [34], and to the effect of series resistances (R s ) [51]. Indeed, the R s has a significant influence on the I-V curve in the high voltage range exceeding 0.6 V, revealing a saturated behavior.…”

Schottky characteristics of Pt contacts on (11–22) semipolar n-type GaN grown on m-plane sapphire substrates

“…It is noted that the obtained ideality factors are in good agreement with those obtained from the TE model (2.19), indicating that the use of the TFE model is reasonable. [22] However, the Φ B value obtained from the TFE model was much larger than that obtained from the pure TE model, while it is comparable to that obtained from the barrier inhomogeneity model. This indicates that the Schottky parameters can be adequately characterized using the barrier inhomogeneity and TFE models.…”

“…Very recently, the TFE model was also suggested to be highly accurate for lightly doped semiconductors if the Schottky diodes exhibit anomalous I-V-T behavior. [20] Therefore, the use of the TFE model shown below is expected to be appropriate: [20][21][22] (4)…”

Excellent Schottky Characteristics of Indium-tin-oxide Contact to n-type GaN

“…Here, note that the n value, which was calculated using the relation of n=(E00/kT)coth(E00/kT), was much larger than 1.0 for all cases, indicating that non-ideal carrier transport occurred at the ITO contact interface. According to previous studies, [15,16] carrier transport through surface states associated with point defects such as nitrogen vacancies or oxygen interstitials (generated during ITO sputtering) or threading dislocations might be responsible for the nonideal transport at the contact interface. Notably, however, the n value decreased significantly with post-thermal annealing, indicating that the density of surface states were reduced.…”

“…To analyze the transport mechanism of ITO contact/nGaN system, the forward I-V curves were analyzed using a thermionic field emission (TFE) theory [14,15] because the calculated characteristic tunneling parameter (E 00 ) of 1.46 lies in the TFE regime, i.e., kT/qE 00 ~ 1 for TFE, where, k is the Boltzmann constant, T is the temperature, q is the electronic charge. Here, the E 00 was estimated according to 2 / 1 * 00…”