Exploring oxygen-affinity-controlled TaN electrodes for thermally advanced TaOx bipolar resistive switching

Abstract

Recent advances in oxide-based resistive switching devices have made these devices very promising candidates for future nonvolatile memory applications. However, several key issues remain that affect resistive switching. One is the need for generic alternative electrodes with thermally robust resistive switching characteristics in as-grown and high-temperature annealed states. Here, we studied the electrical characteristics of Ta2O5−x oxide-based bipolar resistive frames for various TaNx bottoms. Control of the nitrogen content of the TaNx electrode is a key factor that governs variations in its oxygen affinity and structural phase. We analyzed the composition and chemical bonding states of as-grown and annealed Ta2O5−x and TaNx layers and characterized the TaNx electrode-dependent switching behavior in terms of the electrode’s oxygen affinity. Our experimental findings can aid the development of advanced resistive switching devices with thermal stability up to 400 °C.

Enhanced dielectric properties with a significantly reduced loss tangent in (Mg2+, Al3+) co-doped CaCu3Ti4O12ceramics: DFT and experimental investigations

“…The first oxygen peak depicts oxygen bonded in the lattice (O L ), while the second oxygen peak indicates oxygen-deficient, showing the presence of unbounded oxygen molecules or V O . 45 The ratios between O L /V O of the CCTO and Mg05Al05 ceramics were 59.81/40.19 and 67.51/32.49%, respectively. Interestingly, the XPS specifies that the substitutions of Mg 2+ and Al 3+ into the CCTO lattice could suppress oxygen loss during the sintering process at relatively high temperatures (V O decreased), which is consistent with the computational results.…”

Bi-Doped Single-Crystalline (001) Epitaxial TiO2 Anatase Nanostructures for Resistive Random Access Memory Applications

“…Although various RS models have been proposed, many reports attribute the RS effect to migration of the oxygen vacancies away/toward the surface. [1][2][3]12,21 For example, a report on the Ag/TiO 2 /Nb:STO heterojunction suggests that the origin of the observed switching is due to the variation of the Schottky barrier width modulated by the vacancies. 27 In our heterostructures, however, with the same current direction, the best fitting obtained for HRS is the PF emission.…”

“…Metal oxide nanostructures (MONS) have been intensively investigated for use as resistive random access memories (ReRAMs) that possess high density, fast performance speed, and low power consumption. − The working principle of the ReRAM is simply based on the resistance switching (RS) phenomenon occurring in metal oxides under an externally applied electric field. As RS initiates, microscopic redistribution of defects/ions occurs in response to an applied electric field, leading to stoichiometric reconfiguration of the material and subsequent modification of the switching material’s chemical composition and physical properties. − In general, the physical properties of MONS depend on their shape, size, and phase and, furthermore, in the case of single-crystalline epitaxial nanostructures, on their orientation. − Epitaxial nanocrystal arrays offer two significant advantages compared to randomly textured nanostructures (NS). − First, interfacial and bulk properties can be different and independent of each other without compromising the other. A notable example of this is the epitaxial nickel oxide (NiO) nanostructures fabricated on Nb:SrTiO 3 (Nb:STO) substrate, where the interface offers better control on the carrier density; , instead, the metal/NiO/metal device structure can be realized on the basis of the bulk carrier density.…”

“…To realize a very high density (terabit) RS device, it is necessary to identify the underpinning factors at nanoscale, particularly at the interfaces . Popular models put forward to explain any observed RS phenomena fall broadly into two categories: namely, either a conducting filament or interface traps under an external stimulus of an applied electric field. , In these models, the percolation of simple defects in nonstoichiometric films, such as metal interstitials (M i n + ) or oxygen vacancies (V O 2+ ), may also be responsible. ,,− The filament type RS involves the alignment of the oxygen vacancies in conducting channels and is nonvolatile during data retrieval. On the other hand, oxide interfaces have oxygen vacancies as minority carriers.…”

Ternary Logic with Stateful Neural Networks Using a Bilayered TaOX‐Based Memristor Exhibiting Ternary States

“…The O 1s spectra of both layers are shown in Figure 1c , of which results are consistent with the Ta 4f spectra. [ 43 , 44 ] The blue peak located at 530 eV (O I ) and the green peak at 531 eV (O II ) are related to Ta—O bonding in a stoichiometric Ta 2 O 5 and oxygen‐deficient one, respectively. The area ratio of O I (blue)/O II (green) is 3.57 in the TaO X − , and 5.0 in the TaO X ± , confirming TaO X − is more oxygen‐deficient.…”