With recent progress in material science, resistive random access memory (RRAM) devices have attracted interest for nonvolatile, low-power, nondestructive readout, and high-density memories. Relevant performance param...With recent progress in material science, resistive random access memory (RRAM) devices have attracted interest for nonvolatile, low-power, nondestructive readout, and high-density memories. Relevant performance parameters of RRAM devices include operating voltage, operation speed, resistance ratio, endurance, retention time, device yield, and multilevel storage. Numerous resistive-switching mechanisms, such as conductive filament, space-charge-limited conduction, trap charging and discharging, Schottky Emission, and Pool-Frenkel emission, have been proposed to explain the resistive switching of RRAM devices. In addition to a discussion of these mechanisms, the effects of electrode materials, doped oxide materials, and different configuration devices on the resistive-switching characteristics in nonvolatile memory applications, are reviewed. Finally, suggestions for future research, as well as the challenges awaiting RRAM devices, are given.展开更多
In this paper, improvements of resistive random access memory (RRAM) using doping technology are summarized and analyzed. Based on a Cu/ZrO2/Pt device, three doping technologies with Ti ions, Cu, and Cu nanocrystal, r...In this paper, improvements of resistive random access memory (RRAM) using doping technology are summarized and analyzed. Based on a Cu/ZrO2/Pt device, three doping technologies with Ti ions, Cu, and Cu nanocrystal, respectively, are adopted in the experiments. Compared to an undoped device, improvements focus on four points: eliminating the electroforming process, reducing operation voltage, improving electrical uniformity, and increasing device yield. In addition, thermal stability of the high resistance state and better retention are also achieved by the doping technology. We demonstrate that doping technology is an effective way of improving the electrical performance of RRAM.展开更多
The combination of capacitance-and current-voltage(CV/IV) measurements is used to analyze trap generation in silicon-nanocrystal memory devices during Fowler-Nordheim(FN) programming/erasing cycling.CV and IV curves a...The combination of capacitance-and current-voltage(CV/IV) measurements is used to analyze trap generation in silicon-nanocrystal memory devices during Fowler-Nordheim(FN) programming/erasing cycling.CV and IV curves are measured after certain P/E cycles.The flatband voltage(Vfb) and the threshold voltage(Vth) are extracted from CV curves by solving one-dimensional Schr?dinger and Poisson equations.Both hole and electron trappings are observed in the tunneling SiO2.They show up in the accumulation and the inversion,respectively.By fitting FN tunneling current,the area densities of cycling-induced electron traps in the blocking oxide and in the tunneling oxide are finally determined.展开更多
Resistive random access memory (RRAM) has received significant research interest because of its promising potential in terms of down-scaling,high density,high speed and low power. However,its endurance,retention and u...Resistive random access memory (RRAM) has received significant research interest because of its promising potential in terms of down-scaling,high density,high speed and low power. However,its endurance,retention and uniformity are still imperfect. In this article,the physical mechanisms of filament-type RRAM and the approaches for improving the switching performance,including doping,process optimization and interface engineering,are introduced.展开更多
文摘With recent progress in material science, resistive random access memory (RRAM) devices have attracted interest for nonvolatile, low-power, nondestructive readout, and high-density memories. Relevant performance parameters of RRAM devices include operating voltage, operation speed, resistance ratio, endurance, retention time, device yield, and multilevel storage. Numerous resistive-switching mechanisms, such as conductive filament, space-charge-limited conduction, trap charging and discharging, Schottky Emission, and Pool-Frenkel emission, have been proposed to explain the resistive switching of RRAM devices. In addition to a discussion of these mechanisms, the effects of electrode materials, doped oxide materials, and different configuration devices on the resistive-switching characteristics in nonvolatile memory applications, are reviewed. Finally, suggestions for future research, as well as the challenges awaiting RRAM devices, are given.
基金supported by the National Basic Research Program of China (2010CB934200, 2008CB925002)the National Natural Science Foundation of China (60825403, 50972160)the National High-Tech Research & Development Program of China (2008AA031403, 2009AA03Z306)
文摘In this paper, improvements of resistive random access memory (RRAM) using doping technology are summarized and analyzed. Based on a Cu/ZrO2/Pt device, three doping technologies with Ti ions, Cu, and Cu nanocrystal, respectively, are adopted in the experiments. Compared to an undoped device, improvements focus on four points: eliminating the electroforming process, reducing operation voltage, improving electrical uniformity, and increasing device yield. In addition, thermal stability of the high resistance state and better retention are also achieved by the doping technology. We demonstrate that doping technology is an effective way of improving the electrical performance of RRAM.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB934200)the National Natural Science Foundation of China (Grant No. 60825403)the Hi-Tech Research and Development Program of China ("863" Program) ( Grant No. 2008AA031403)
文摘The combination of capacitance-and current-voltage(CV/IV) measurements is used to analyze trap generation in silicon-nanocrystal memory devices during Fowler-Nordheim(FN) programming/erasing cycling.CV and IV curves are measured after certain P/E cycles.The flatband voltage(Vfb) and the threshold voltage(Vth) are extracted from CV curves by solving one-dimensional Schr?dinger and Poisson equations.Both hole and electron trappings are observed in the tunneling SiO2.They show up in the accumulation and the inversion,respectively.By fitting FN tunneling current,the area densities of cycling-induced electron traps in the blocking oxide and in the tunneling oxide are finally determined.
基金supported by the National Basic Research Program of China (2010CB934200 and 2008CB925002)the National Natural Science Foundation of China (60825403 and 50972160)the National High-Tech Research & Development Program of China (2008AA031403 and 2009AA03Z306)
文摘Resistive random access memory (RRAM) has received significant research interest because of its promising potential in terms of down-scaling,high density,high speed and low power. However,its endurance,retention and uniformity are still imperfect. In this article,the physical mechanisms of filament-type RRAM and the approaches for improving the switching performance,including doping,process optimization and interface engineering,are introduced.
