Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive r...Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive resistive states in response to an external electrical stimulus has been demonstrated. Through years of selection, cells based on the drift of metal ions, namely conductive-bridge memory devices, have shown a wide range of applications with nanosecond switching speeds, nanometer scalability, high-density, and low power-consumption. However, for low （sub-10-~A） current operation, a critical challenge is still represented by programming variability and by the stability of the conductive filament over time. Here, by introducing the concept of reverse filament growth （RFG）, we managed to control the structural reconfiguration of the conductive filament inside a memory cell with significant enhancements of each of the aforementioned properties. A first-in-class Cu-based switching device is demonstrated, with a dedicated stack that enabled us to systematically trigger RFG, thus tuning the device＇s properties. Along with nanosecond switching speeds, we achieved an endurance of up to 106 cycles with a 102 read window, with outstanding disturb immunity and optimal stability of the filament over time. Furthermore, by tuning the filament＇s shape, an excellent control of multi-level bit operations was achieved. Thus, this device offers high flexibility in memory applications.展开更多
Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM...Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM. It has been revealed that the growth direction and geometry of the conductive filament are controlled by the ion migration rate in the electrolyte layer during the formation procedure. When the migration rate is rela- tive high, the filament is shown to grow from cathode to anode. When the migration rate is low, the growth direction is expected to start from the anode. Simulated conductive filament （CF） geometries and I-V characteristics are also illustrated and analyzed. A good agreement between the simulation results and experiment data is obtained.展开更多
文摘Nonvolatile memory devices based on filamentary resistance switching （KS） are among the frontrunners to fuel future devices and sensors of the internet of things （IoT） era. The capability of many two distinctive resistive states in response to an external electrical stimulus has been demonstrated. Through years of selection, cells based on the drift of metal ions, namely conductive-bridge memory devices, have shown a wide range of applications with nanosecond switching speeds, nanometer scalability, high-density, and low power-consumption. However, for low （sub-10-~A） current operation, a critical challenge is still represented by programming variability and by the stability of the conductive filament over time. Here, by introducing the concept of reverse filament growth （RFG）, we managed to control the structural reconfiguration of the conductive filament inside a memory cell with significant enhancements of each of the aforementioned properties. A first-in-class Cu-based switching device is demonstrated, with a dedicated stack that enabled us to systematically trigger RFG, thus tuning the device＇s properties. Along with nanosecond switching speeds, we achieved an endurance of up to 106 cycles with a 102 read window, with outstanding disturb immunity and optimal stability of the filament over time. Furthermore, by tuning the filament＇s shape, an excellent control of multi-level bit operations was achieved. Thus, this device offers high flexibility in memory applications.
基金Project supported by the Ministry of Science and Technology of China(Nos.2010CB934200,2011CBA00602,2009CB930803,2011CB921804,2011AA010401,2011AA010402,XDA06020102)the National Natural Science Foundation of China(Nos.61221004,61274091,60825403,61106119,61106082,61306117)
文摘Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM. It has been revealed that the growth direction and geometry of the conductive filament are controlled by the ion migration rate in the electrolyte layer during the formation procedure. When the migration rate is rela- tive high, the filament is shown to grow from cathode to anode. When the migration rate is low, the growth direction is expected to start from the anode. Simulated conductive filament （CF） geometries and I-V characteristics are also illustrated and analyzed. A good agreement between the simulation results and experiment data is obtained.
