Search

Set and reset characteristics are studied for unipolar and bipolar metal-oxide resistive-switching memory devices. We show a universal dependence of set-state resistance and reset current on the compliance current used during set, with negligible impact of metal-oxide composition and switching condition. An analytical Joule-heating model for universal reset is presented, predicting a weak dependence of reset temperature and voltage on diffusion and migration parameters in both unipolar- and bipolar-switching modes. Data for the reset voltage are shown for a wide range of unipolar and bipolar metal oxides, in support of our calculations. [ABSTRACT FROM AUTHOR]

Resistive-switching memory (RRAM) devices are attracting a considerable interest in view of their back-end integration, fast programming, and high scalability. Prediction the programming voltages and currents as a function of the operating conditions is an essential task for developing compact and numerical models able to handle a large number (106-109) of cells within an array. Based on recent experimental findings on the set and reset processes, we have developed physics-based analytical models for the set and reset operations in NiO-based RRAMs. Simulation results obtained by the analytical models were compared with experimental data for variable pulse conditions and were found consistent with data. The set transition is described by a threshold switching process at the broken conductive filament (CF), while the reset transition is viewed as a thermally driven dissolution and/or oxidation of the CF. Set and reset models are finally used for reliability predictions of failure times under constant-voltage stress (read disturb) and elevated-temperature bake (data retention). [ABSTRACT FROM AUTHOR]

The physical understanding of the programming and reliability mechanisms in resistive-switching memory devices requires a detailed characterization of the electrical and thermal conduction properties in the low-resistance state of the memory cell. The aim of this paper is the characterization of the conductive filament (CF), which controls the localized current flow in the low resistive state of the cell. Based on a new technique for evaluating the CF temperature during operation, we perform a statistical characterization of the critical filament temperature for the reset operation, i.e., the transition to the high-resistance state by the thermal dissolution of the CF. The thermal resistance of the CF and the activation energy for the dissolution mechanism are then evaluated, allowing for a physics-based numerical modeling of the reset operation based on CF thermal breakup. [ABSTRACT FROM AUTHOR]

This paper addresses the numerical modeling of re- set programming in NiO-based resistive-switching memory. In our model, we simulate electrical conduction and heating in the conductive filament (CF), which controls the resistance of the low resistive (or set) state, accounting for CF thermal-activated dissolution. Employing CF electrical and thermal parameters, which were previously characterized on our NiO-based samples, our calculations are shown to match experimental reset and retention characteristics. Simulations show that reset transition is self-accelerated as a consequence of a positive feedback between the thermal dissolution of the CF and local Joule heating in the CF bottleneck, which can account for the abrupt resistance transition. in experimental data. Finally, the model is used to investigate the reduction of the reset current, which is needed for device application. [ABSTRACT FROM AUTHOR]

NiO-based resistive-switching memory (RRAM) is a promising new technology for high-density nonvolatile storage. The main obstacles to practical application are the large and hardly scalable reset (programming) current and the reliability at high temperature. This letter studies temperature-accelerated data retention in RRAM cells from both experimental and theoretical standpoints, addressing the size/nature of the conductive filament and clarifying the tradeoff between data retention and reset current. [ABSTRACT FROM AUTHOR]

This letter addresses the impact of electrode materials on programming characteristics of NiO-based resistive-switching memory devices. The use of noble metals for the electrodes, instead of Si contacts, is shown to result in a lowering of the set/reset voltage. This is ascribed to a different chemical composition of the conductive filament (CF) in the set state for varying electrodes, suggesting that atomic diffusion from the electrodes takes place during the formation of the CF at the set process. The results are interpreted on the basis of numerical simulations of the reset transition, which are compared with experimental data. [ABSTRACT FROM AUTHOR]