Memristive devices are electrical resistance switches that can retain a state of internal resistance based on the history of applied voltage and current. These devices can store and process information, and offer several key performance characteristics that exceed conventional integrated circuit technology. An important class of memristive devices are two-terminal resistance switches based on ionic motion, which are built from a simple conductor/insulator/conductor thin-film stack. These devices were originally conceived in the late 1960s and recent progress has led to fast, low-energy, high-endurance devices that can be scaled down to less than 10 nm and stacked in three dimensions. However, the underlying device mechanisms remain unclear, which is a significant barrier to their widespread application. Here, we review recent progress in the development and understanding of memristive devices. We also examine the performance requirements for computing with memristive devices and detail how the outstanding challenges could be met.

Memristive devices for computing

In this paper, recent progress of binary metal-oxide resistive switching random access memory (RRAM) is reviewed. The physical mechanism, material properties, and electrical characteristics of a variety of binary metal-oxide RRAM are discussed, with a focus on the use of RRAM for nonvolatile memory application. A review of recent development of large-scale RRAM arrays is given. Issues such as uniformity, endurance, retention, multibit operation, and scaling trends are discussed.

Metal–Oxide RRAM

In this paper, we review the recent progress in the resistive random access memory (ReRAM) technology, one of the most promising emerging nonvolatile memories, in which both electronic and electrochemical effects play important roles in the nonvolatile functionalities. First, we provide a brief historical overview of the research in this field. We also provide a technological overview and the epoch-making achievements, followed by an account of the current understanding of both bipolar and unipolar ReRAM operations. Finally, we summarize the challenges facing the ReRAM technology as it moves toward the beyond-2X-nm generation of nonvolatile memories and the so-called beyond complementary metal-oxide-semiconductor (CMOS) device.

Resistive Random Access Memory (ReRAM) Based on Metal Oxides

Resistive Random Access Memory (ReRAM) Based on Metal Oxides This paper reviews a class of metal-oxide-metal resistive memory structures that depend on a chemical oxidation/reduction process to cause a change in resistance when a voltage pulse is applied.

Storage-class memory (SCM) combines the benefits of a solid-state memory, such as high performance and robustness, with the archival capabilities and low cost of conventional hard-disk magnetic storage. Such a device would require a solid-state nonvolatile memory technology that could be manufactured at an extremely high effective areal density using some combination of sublithographic patterning techniques, multiple bits per cell, and multiple layers of devices. We review the candidate solid-state nonvolatile memory technologies that potentially could be used to construct such an SCM. We discuss evolutionary extensions of conventional flash memory, such as SONOS (silicon-oxide-nitride-oxide-silicon) and nanotraps, as well as a number of revolutionary new memory technologies. We review the capabilities of ferroelectric, magnetic, phase-change, and resistive random-access memories, including perovskites and solid electrolytes, and finally organic and polymeric memory. The potential for practical scaling to ultrahigh effective areal density for each of these candidate technologies is then compared.

Overview of candidate device technologies for storage-class memory

A non-volatile resistive switching mechanism based on trap-related space-charge-limited-conduction (SCLC) is proposed Excellent memory characteristics have been demonstrated using near-stoichiometric cuprous oxide (CuxO) metal-insulator-metal (MIM) structures: low-power operation, fast switching speed, superior temperature characteristics, and long retention This MIM memory cell is fully compatible with standard CMOS process The proposed switching mechanism is a strong contender for high density and low cost memory applications

Non-volatile resistive switching for advanced memory applications

A Metal-Insulator-Metal (MIM) device based on a Cu2O insulator has electrical characteristics significantly dependent on the oxide to top electrode (TE) interface. Cu/Cu2O/TE devices with various top electrodes have different thermal release characteristics, related to trap depth. The behavior of the device during erase with Ni and Ti top electrodes suggests different mechanisms. This paper focuses on Cu/Cu2O/Ni devices and proposes a thermal erase model, based on power calculations and temperature dependence.

M. VanBuskirk

Papers

Non-volatile resistive switching for advanced memory applications

Erase mechanism for copper oxide resistive switching memory cells with nickel electrode