The invention provides a resistive memory with better area efficiency without degrading reliability, which includes an array area, word lines, a local source line, bit lines, and a shared source line. In the array area, memory cells are arranged in a matrix, and each memory cells includes a variable resistance element and an accessing transistor. The word lines extend in a row direction of the array area and are connected to the memory cells in the row direction. The local source line extends in a column direction of the array area. The bit lines extend in the column direction and are connected to first electrodes of the memory cells in the column direction. The shared source line is connected to the local source line. The shared source line extends in the row direction and is connected to second electrodes of the memory cells in the row direction.

A device includes at least one tunable resistive element. Each tunable resistive element comprises a first terminal, a second terminal, and a dielectric layer arranged between the first and second terminals. The device is configured to apply at least one electrical set pulse to the resistive elements to form a conductive filament comprising a plurality of oxygen vacancies in the dielectric layer. The device is configured to apply at least one electrical reset pulse to displace a subset of the oxygen vacancies of the conductive filament. The at least one electrical reset pulse comprises a first part, which is adapted to increase the temperature of the conductive filament and increase the mobility of the oxygen vacancies of the conductive filament, and a second part, which is configured to displace the subset of the oxygen vacancies of the conductive filament.

Methods, systems, and devices related to techniques to access a self-selecting memory device are described. A self-selecting memory cell may store one or more bits of data represented by different threshold voltages of the self-selecting memory cell. A programming pulse may be varied to establish the different threshold voltages by modifying one or more time durations during which a fixed level of voltage or current is maintained across the self-selecting memory cell. The self-selecting memory cell may include a chalcogenide alloy. A non-uniform distribution of an element in the chalcogenide alloy may determine a particular threshold voltage of the self-selecting memory cell. The shape of the programming pulse may be configured to modify a distribution of the element in the chalcogenide alloy based on a desired logic state of the self-selecting memory cell.

A memory comprising: a resistive-switching element having first and second electrodes separated by a layer of insulator; an energy storage component or load coupled to the resistive-switching element via a first switch; and a control circuit configured: to program the resistive-switching element to have a set state, wherein, in the set state, a filament forms a conducting path between the first and second electrodes; and, following a dissolution of the filament, to recover electrical energy, generated by the dissolution of the filament, from one of the first and second electrodes by activating the first switch.

According to an embodiment, a phase-change memory device comprises: an upper electrode and a lower electrode; a phase-change layer in which a crystal state thereof is changed by heat supplied by the upper electrode and the lower electrode; and a selector which selectively switches the heat supplied by the upper electrode and the lower electrode to the phase-change layer, wherein the selector is formed of a compound which includes a transition metal in the phase-change material so as to have a high resistance when the crystalline state of the selector is crystalline and so as to have a low resistance when the crystalline state of the selector is non-crystalline.

Methods, systems, and devices for operating memory cell(s) are described. A resistance of a storage element included in a memory cell may be programmed by applying a voltage to the memory cell that causes ion movement within the storage element, where the storage element remains in a single phase and has different resistivity based on a location of the ions within the storage element. In some cases, multiple of such storage elements may be included in a memory cell, where ions within the storage elements respond differently to electric pulses, and a non-binary logic value may be stored in the memory cell by applying a series of voltages or currents to the memory cell.

An embodiment non-volatile memory device includes an array of memory cells in rows and columns; a plurality of local bitlines, the memory cells of each column being coupled to a corresponding local bitline; a plurality of main bitlines, each main bitline being coupleable to a corresponding subset of local bitlines; a plurality of program driver circuits, each having a corresponding output node and injecting a programming current in the corresponding output node, each output node coupleable to a corresponding subset of main bitlines. Each program driver circuit further includes a corresponding limiter circuit that is electrically coupled, for each main bitline of the corresponding subset, to a corresponding sense node whose voltage depends, during writing, on the voltage on the corresponding main bitline. Each limiter circuit turns off the corresponding programming current, in case the voltage on any of the corresponding sense nodes overcomes a reference voltage.

Subject matter disclosed herein may relate to correlated electron switches.

A phase-change memory cell is formed by a heater, a crystalline layer disposed above the heater, and an insulating region surrounding sidewalls of the crystalline layer. The phase-change memory cell supports programming with a least three distinct data levels based on a selective amorphization of the crystalline layer.

The present disclosure includes apparatuses, methods, and systems for sensing two memory cells to determine one data value. An embodiment includes a memory having a plurality of memory cells and circuitry configured to sense memory states of each of two memory cells to determine one data value. One data value is determined by sensing the memory state of a first one of the two memory cells using a first sensing voltage in a sense window between a first threshold voltage distribution corresponding to a first memory state and a second threshold voltage distribution corresponding to a second memory state and sensing the memory state of a second one of the two memory cells using a second sensing voltage in the sense window. The first and second sensing voltages are selectably closer in the sense window to the first threshold voltage distribution or the second threshold voltage distribution.