Abstract:
A threshold device including a plurality of adjacent tunnel barrier layers that are in contact with one another and are made from a plurality of different dielectric materials is disclosed. A memory plug having first and second terminals includes, electrically in series with the first and second terminals, the threshold device and a memory element that stores data as a plurality of conductivity profiles. The threshold device is operative to impart a characteristic I-V curve that defines current flow through the memory element as a function of applied voltage across the terminals during data operations. The threshold device substantially reduces or eliminates current flow through half-selected or un-selected memory plugs and allows a sufficient magnitude of current to flow through memory plugs that are selected for read and write operations. The threshold device reduces or eliminates data disturb in half-selected memory plugs and increases S/N ratio during read operations.
Abstract:
A memory cell including conductive oxide electrodes is disclosed. The memory cell includes a memory element operative to store data as a plurality of resistive states. The memory element includes a layer of a conductive metal oxide (CMO) (e.g., a perovskite) in contact with an electrode that may comprise one or more layers of material. At least one of those layers of material can be a conductive oxide (e.g., a perovskite such as LaSrCoO3-LSCoO or LaNiO3-LNO) that is in contact with the CMO. The conductive oxide layer can be selected as a seed layer operative to provide a good lattice match with and/or a lower crystallization temperature for the CMO. The conductive oxide layer may also be in contact with a metal layer (e.g., Pt). The memory cell additionally exhibits non-linear IV characteristics, which can be favorable in certain arrays, such as non-volatile two-terminal cross-point memory arrays.
Abstract:
A memory using a tunnel barrier that has a variable effective width is disclosed. A memory element includes a tunneling barrier and a conductive material. The conductive material typically has mobile ions that either move towards or away from the tunneling barrier in response to a voltage across the memory element. A low conductivity region is either formed or destroyed. It can be formed by either the depletion or excess ions around the tunneling barrier, or by the mobile ions combining with complementary ions. It may be destroyed by either reversing the forming process or by reducing the tunneling barrier and injecting ions into the conductive material. The low conductivity region increases the effective width of the tunnel barrier, making electrons tunnel a greater distance, which reduces the memory element's conductivity. By varying conductivity multiple states can be created in the memory cell.
Abstract:
A multi-layer non-volatile memory integrally formed on top of a substrate including active circuitry is disclosed. Each layer of memory includes memory cells (e.g., a two-terminal memory cell) having a multi-resistive state material layer that changes its resistive state between a low resistive state and a high resistive state upon application of a write voltage across the memory cell. Data stored in the memory cells can be non-destructively determined by applying a read voltage across the memory cells. Data storage capacity can be tailored to a specific application by increasing or decreasing the number of memory layers that are integrally fabricated on top of the substrate (e.g., more than four layers or less than four layers). The memory cells can include a non-ohmic device for allowing access to the memory cell only during read and write operations. Each memory layer can comprise a cross point array.
Abstract:
Device fabrication is disclosed, including forming a first part of a device at a first fabrication facility as part of a front-end-of-the-line (FEOL) process, the first part of the device comprising a base wafer formed by FEOL processing, and subsequently performing one or more back-end-of-the-line (BEOL) processes at a second fabrication facility to form an IC, the one or more BEOL processes comprising finishing the forming of the device (e.g., an IC including memory) by depositing one or more memory layers on the base wafer. FEOL processing can be used to form active circuitry die (e.g., CMOS circuitry on a Si wafer) and BEOL processing can be used to form on top of each active circuitry die, one or more layers of cross-point memory arrays formed by thin film processing technologies that may or may not be compatible with or identical to some or all of the FEOL processes.
Abstract:
A movable terminal in a two terminal memory array. A storage medium is disposed between two terminals, one of the terminals being movable relative to the second terminal. Either one of the terminals or both terminals might actually move, resulting in one terminal being moved relative to the other terminal. A memory element disposed between the two terminals has a conductance that is responsive to a write voltage across the electrodes.
Abstract:
A memory including reference cells is provided. The memory has address decoding circuitry and an array of memory cells that are non-volatile and re-writable. Each memory cell has a two terminal memory plug that is capable of experiencing a change in resistance. Sensing circuitry compares activated memory cells to a reference level. The reference level is typically generated by at least one reference cell that can be selected at the same time the memory cell is selected.
Abstract:
A two-terminal memory array includes a plurality of first and second conductive traces. An address unit operatively applies a select voltage across a selected pair of the first and second conductive traces and applies a non-select voltage potential to unselected traces. A total current flowing in the selected first conductive trace and a leakage current flowing through unselected second conductive traces are sensed by a sense unit in a one cycle or a two cycle pre-read operation. The total and leakage currents can be combined with a reference signal to derive a data signal indicative of one of a plurality of conductivity profiles that represent stored data. The conductivity profiles can be stored in a resistive state memory element that is electrically in series with the selected first and second conductive traces.
Abstract:
A treated conductive element is provided. A conductive element can be treated by depositing either a reactive metal or a very thin layer of material on the conductive element. The reactive metal (or very thin layer of material) would typically be sandwiched between the conductive element and an electrode. The structure additionally exhibits non-linear IV characteristics, which can be favorable in certain arrays.
Abstract:
A memory including reference cells is provided. The memory has address decoding circuitry and an array of memory cells that are non-volatile and re-writable. Each memory cell has a two terminal memory plug that is capable of experiencing a change in resistance. Sensing circuitry compares activated memory cells to a reference level. The reference level is typically generated by at least one reference cell that can be selected at the same time the memory cell is selected.