Modeling of Breakdown-Limited Endurance in Spin-Transfer Torque Magnetic Memory under Pulsed Cycling Regime

Perpendicular spin-transfer torque (p-STT) magnetic memory is gaining increasing interest as a candidate for storage-class memory, embedded memory, and possible replacement of static/dynamic memory. All these applications require extended cycling endurance, which should be based on a solid understanding and accurate modeling of the endurance failure mechanisms in the p-STT device. This paper addresses cycling endurance of p-STT memory under pulsed electrical switching. We show that endurance is limited by the dielectric breakdown of the magnetic tunnel junction stack, and we model endurance lifetime by the physical mechanisms leading to dielectric breakdown. The model predicts STT endurance as a function of applied voltage, pulsewidth, pulse polarity, and delay time between applied pulses. The dependence of the endurance on sample area is finally discussed

Bipolar resistance switching in the Pt/WOx/W nonvolatile memory devices

We reported the resistive switching behavior in the Pt/WOx/W memory device fabricated with fully room temperature process. The devices show high resistance ratio (>140), reliable data retention at 85 °C and fast switching (100 ns). The field-induced res

Improved resistive switching properties in Pt/Pr0.7Ca 0.3MnO3/Y2O3-stabilized ZrO 2/W via-hole structures

An yttria-stabilized zirconia (YSZ) (∼10 nm) layer was designed and introduced by a pulse laser deposition method before a Pr0.7Ca0.3MnO3 (PCMO) film was deposited on the W bottom electrode (BE) with a sub-micron via-hole structure. Comparing Pt/PCMO/

Resistive switching mechanism of a Pr0.7Ca0.3MnO3-based memory device and assessment of its suitability for nano-scale applications

In this work, various nano-scale Pr0.7Ca0.3MnO3(PCMO)-based memory devices with electrode diameters of 250 nm were fabricated, and the effect of the metal electrode/PCMO interface on resistive switching (RS) for PCMO-based resistive random access memories, is systematically investigated. The switching behavior could be improved not only by using a reactive metal (W and Al) but also by inserting a thin oxide tunnel barrier layer (yttria-stabilized zirconia, i.e., YSZ) or a dielectric Al2O3 layer between the electrode and the PCMO film

Resistive switching characteristics and mechanism of thermally grown WOx thin films

Resistive switching characteristics of thermally oxidized tungsten thin films and their switching mechanism were investigated, modifying thickness of the active layer (WOx) by varying oxidation conditions. Two types of switching were observed in Pt/WOx/

Asymmetric bipolar resistive switching in solution-processed Pt/TiO 2/W devices

The resistive switching characteristics of Pt/TiO2/W devices in a submicrometre via-hole structure are investigated. TiO2 film is grown by the sol-gel spin coating technique. The device exhibits reversible and reproducible bistable resistive switching with a rectifying effect. The Schottky contact at the Pt/TiO2 interface limits electron injection under reverse bias resulting in a rectification ratio of >60 at 2 V in the low-resistance state. The switching mechanism in our device can be interpreted as an anion migration-induced redox reaction at the tungsten bottom electrode (W). The rectifying effect can significantly reduce the sneak path current in a crossbar array and provide a feasible way to achieve high memory density

Highly uniform and reliable resistance switching properties in bilayer WO x/NbO x RRAM devices

Memory performances, especially uniformity and reliability of resistance random access memory (RRAM) devices with W/NbOx/Pt structures were investigated. Scaling down the active device area (φ = 250 nm) can significantly minimize extrinsic defects relat