Electron transport in Ta2O5 films

On a current mechanism in Ta2O5 thin films

“…Such behaviour of the lnI against 1/T dependences obtained in Ta 2 O 5 films can be explained by neither the FP nor Schottky mechanism because these mechanisms predict only a linear dependence of lnI on 1/T . Therefore, in order to explain the observed peculiarities of current dependence on temperature and applied voltage, the phonon-assisted tunnelling (PhAT) model, which was formerly used for describing similar data measured in some diodes [6,14,15], will be used.…”

“…There are many studies on the leakage current mechanism in thin films grown by various methods, with different electrode materials deposited on different substrates [2][3][4][5][6][7][8][9][10][11][12][13]. Leakage current-voltage characteristics have been explained in most cases by the Frenkel-Poole (FP) mechanism (bulk limited currents) [3][4][5][7][8][9][10][11][12][13] or by the Schottky emission of electrons from electrodes [2,7].…”

“…The authors of [7] decline the possible tunnelling mechanism of conduction because, in their mind, Fowler-Nordheim tunnelling is inherently independent of the temperature, while the current exhibited an obvious dependence on temperature. However, in [6] it was shown that temperature-dependent I − V characteristics can be successfully explained on the basis of phonon-assisted tunnelling, which is an inherently temperature dependent tunnelling process. Nevertheless, in a series of recently published works [10][11][12][13], the authors also point to Frenkel emission as the dominant mechanism of current in metal/Ta 2 O 5 /Si structures.…”

Comment on “(Ta1−xNbx)2O5 films produced by atomic layer deposition: Temperature dependent dielectric spectroscopy and room-temperature I–V characteristics” [J. Appl. Phys. 90, 4532 (2001)]

“…10,11 On the basis of the multiphononassisted tunneling theory, the temperature variation of I -V characteristics in Ta 2 O 5 films has been successfully explained in Ref. 12 The comparison shows reasonable agreement. However, in the lower field region ͑Ͻ10 MV/m͒, a slower decrease of current with field is observed compared to the corresponding decrease of tunneling rate.…”

Transport mechanism in mica and SiO2 dielectrics

“…In Refs. [18,19] the current dependence on bias voltage in some dielectrics at different temperatures has been explained by the phonon-assisted tunnelling theory [22]. This quantum-mechanical theory is the more common theory of tunnelling, i.e.…”