Improvement of Resistive Switching Uniformity by Introducing a Thin NbOx Interface Layer

Preparation, characterization, and electrical properties of epitaxial NbO2thin film lateral devices

“…In contrast to the previous reports [3][4][5][6][7] where non-connected conducting filaments preexisted and/or were modified by electroforming in non-stoichiometric and amorphous NbO x phases, we observed volatile and reversible switching in the epitaxial quality NbO 2 films with minimal non-stoichiometry and with no electroforming steps required. Therefore we assume that threshold switching in our devices follows conduction paths associated with defects such as twin domain boundaries, in which thermally confined filaments are locally heated above the MIT temperature [39,40,41].…”

“…The thresholdelectric field magnitude was found to be E th =2.2 X 10 6 V/m. Typical threshold fields reported for vertical devices are on the order of 10 8 V/m [5,7]. Thus, a purely electric field-induced effect is unlikely to be the cause of the observed switching.…”

“…Recently there has been a growing interest in materials demonstrating metal-insulator transitions (MITs) because of their possible applications in electronic devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Among these materials is NbO 2 which exhibits one of the highest MIT temperatures of 1081K [16][17], accompanied by a structural transition from a distorted rutile (low temperature) to a rutile structure (high temperature phase).…”

The role of defects in the electrical properties of NbO2 thin film vertical devices

“…[1][2][3][4][5][6] NbO 2 exhibits a thermally driven MIT at T MIT = 1081 K, 7,8 which is accompanied by a structural transition from a distorted rutile to a rutile structure with increasing temperature. It is also possible to induce MIT in NbO 2 by applying an electric field, where joule heating produced by the applied electric field can easily cause this material to undergo a MIT.…”

Improved resistive switching properties by nitrogen doping in tungsten oxide thin films

“…Thus, the control of the localized CFs in WO x thin films is a key factor when enhancing the RS properties of WO x -based RRAM. Several studies have been performed to control CF generation by the insertion of metal doping, and Si introduction [9,10]. Recently, Liu et al reported that an additional layer of NbO x between the WO 3-x layer and the Pt bottom layer improved the RS properties of a WO x memory cell because the NbO x layer helps to localize the position of the CF path.…”