Electrode dependence of resistance switching in polycrystalline NiO films

Abstract

We investigated resistance switching in top-electrode/NiO∕Pt structures where the top electrode was Au, Pt, Ti, or Al. For Pt∕NiO∕Pt and Au∕NiO∕Pt structures with ohmic contacts, the effective electric field inside the film was high enough to induce trapping or detrapping at defect states and thus resistance switching. For a Ti∕NiO∕Pt structure with well-defined Schottky contact at Ti∕NiO interface accompanied by an appreciable voltage drop, the effective electric field inside the NiO film was not enough to induce resistance switching. For an Al∕NiO∕Pt structure with a low Schottky barrier at the Al∕NiO interface, resistance switching could be induced at a higher voltage since the voltage drop at the Al∕NiO interface was not negligible but small.

Atomic Layer Deposition of NiO by the Ni(thd)2/H2O Precursor Combination

“…[8][9][10][11][12][13][14][15] In many of the applications mentioned above, deposition techniques capable of yielding good step coverage on complex-shaped substrate surfaces, and good uniformity in terms of thickness and properties, are essential. These requirements make ALD an interesting technique for the deposition of NiO films, particularly as the dimensions of the device structures are continually being reduced.…”

An overview of resistive random access memory devices

“…Because the work functions of different electrodes can vary considerably, the type of contact between an electrode and a resistive-switching layer can be determined by Ohmic or Schottky contact. For Ohmic contact, the voltage drop at an electrode/resistive-switching layer interface can be negligible, and the effective electric field inside the resistive-switching film is high enough to induce resistive switching [12,13]. For Schottky contact, if a low Schottky barrier is formed, the voltage drop at an electrode/resistive switching layer interface is small but not negligible [12].…”

“…For Ohmic contact, the voltage drop at an electrode/resistive-switching layer interface can be negligible, and the effective electric field inside the resistive-switching film is high enough to induce resistive switching [12,13]. For Schottky contact, if a low Schottky barrier is formed, the voltage drop at an electrode/resistive switching layer interface is small but not negligible [12]. On the other hand, if the Schottky barrier height is quite large, the voltage drop at an electrode/ resistive-switching layer interface is appreciable and the effective electric field inside the resistive-switching film is insufficient to induce resistive switching [13].…”

Effect of change in number of conduction electrons on the spin configuration in transition metal oxides

“…[8] Several hypotheses have been proposed to explain the conductivity switching phenomena. 'Domain tunneling model' [9] and Schottky model [6] are two such examples. Another leading hypothesis is that conductivity switching originates from the repetitive formation and rupturing of a conducting filament in the transition metal oxide matrix [3] Although numerous studies have been done on the transport properties of the transition metal oxides (cf, e.g.…”

“…The bistable conductivity switching phenomena have been observed in many kinds of transition metal oxides, such as NB 2 O 5 , [1] TiO 2 , [2] NiO [3 -5] nonstoichiometric ZrO x , [6] Cr-dopedSrZrO 3 , [7] and Pr 1−x Ca x MnO 3 . [8] Several hypotheses have been proposed to explain the conductivity switching phenomena.…”