Temperature dependence of barrier height inhomogeneity in β-Ga2O3 Schottky barrier diodes

Abstract

From an analysis of Pd contact Schottky diodes fabricated on (100) β-Ga2O3 wafers, in combination with data extracted from published work, we show that the barrier height inhomogeneity commonly observed in β-Ga2O3 Schottky diodes has a strong correlation to the temperature. For doping of ∼5 × 1017 cm−3, the barrier height arising from an inhomogeneous contact continues to increase to a temperature of ∼440 K followed by a decrease upon a further increase in temperature, which is commonly attributed to the bandgap narrowing of the semiconductor referred to as the Varshni shift. At this regime, Schottky characteristics representing close to homogeneous behavior is obtained. Thus, a device under normal operating conditions in a system, which results in an elevated temperature, is expected to exhibit near-homogeneous electrical characteristics.

Nanoscale Characterization of Chemical and Structural Properties of the Au/(100) β-Ga2O3 Interface

“…In contrast, φ B JV and φ B CV obtained for the Ni/β-Ga 2 O 3 contacts were in close agreement, with values of 1.21 and 1.25 eV, respectively. Differences between φ B JV and φ B CV are also generally attributed to spatial inhomogeneities of the Schottky barrier. − Additionally, the difference between φ B JV and φ B CV can also be attributed to different current transport mechanisms. For example, Wang et al attributed the difference for φ B JV and φ B CV in Au/GaN Schottky diodes to recombination via Ga vacancies left behind due to Ga diffusion into the Au overlayer .…”

Impedance Spectroscopy on Hafnium Oxide‐Based Memristive Devices

“…From the linear fit of the effective barrier height as a function of temperature (Figure 6b), the temperature coefficient can be determined using Equations ( 11) and ( 6): α φ = 2.38 ±~0.46 × 10 −3 eV K −1 for the reduction of the barrier height (dφ B /dT) and effective barrier height at room temperature φ B (T = 293) = 0.82 eV. [61] TEM images show local inhomogeneity in the barrier (Figure 2a) that most likely causes spatial potential fluctuations and thus leads to an effective barrier increase with temperature. [42] Yet, this effect seems to be dominated by band narrowing (Varshni shift [62] ), which can be explained by two causes.…”

A review of metal–semiconductor contacts for β-Ga2O3

“…The most commonly used techniques to deposit metals are evaporation through electron beam evaporation or sputtering [80]. For example, Jadhav et al [81] deposited different metals on Ga 2 O 3 substrates using electron beam evaporation to investigate the correlation between temperature and Schottky barrier height, while Hou et al [82] used sputtering to fabricate a metal-Ga 2 O 3 contact and studied the influence of metal oxidation on barrier heights. Actually, the deposition method can influence the barrier height greatly.…”