A memory device includes a cell area in which a plurality of word lines, a plurality of bit lines, and a plurality of memory cells connected to the plurality of word lines and the plurality of bit lines are disposed, each of the plurality of memory cells including an Ovonic threshold switch element and a memory element connected to each other in series, and a peripheral circuit area including at least one peripheral circuit, configured to input a first refresh voltage turning on the Ovonic threshold switch element to each of at least some refresh cells among the plurality of memory cells to execute a refresh operation, determine each of the refresh cells as a first refresh cell in a first state or a second refresh cell in a second state while the Ovonic threshold switch element is turned on, and input a second refresh voltage, different to the first refresh voltage, to the second refresh cell.

A non-volatile memory includes a first semiconductor layer vertically stacked on a second semiconductor layer and including a first memory group, a second memory group, a third memory group and a fourth memory group. The second semiconductor layer includes a first region, a second region, a third region and a fourth region respectively underlying the first memory group, second memory group, third memory group and fourth memory group. The first region includes one driving circuit connected to memory cells of one of the second memory group, third memory group and fourth memory group through a first word line, and another driving circuit connected to memory cells of the first memory group through a first bit line, wherein the first word line and first bit line extend in the same horizontal direction.

Methods, systems, and devices for cross point array architecture for multiple decks are described. A memory array may include multiple decks, such as six or eight decks. The memory array may also include sockets for coupling access lines with associated decoders. The sockets may be included in sub-blocks of the array. A sub-block may be configured to include sockets for multiple access lines. A socket may intersect an access line in the middle of the access line, or at an end of the access line. Sub-blocks containing sockets for an access line may be separated by a period based on the access line.

Various aspects relate to a threshold switch structure and a use of such threshold switch structure as a threshold switch in a memory cell arrangement, the threshold switch structure including: a first electrode, a second electrode, a switch element in direct physical contact with the first electrode and the second electrode, the switch element including a layer of a spontaneously polarizable material. The first electrode, the second electrode, and the switch element are configured to allow for a switching of the switch element between a first electrical conductance state and a second electrical conductance state as a function of a voltage drop provided over the switch element by the first electrode and the second electrode.

The present application provides an apparatus, including: a substrate; a first line electrode formed on the substrate; an interlayer formed on the first line electrode, a selector stack formed on the interlayer and the first line electrode; an RRAM stack formed on the selector stack; and a second line electrode formed on the RRAM stack. The interlayer comprises an upper surface and a sidewall. In some embodiments, a shape of the interlayer comprises a cylinder, a pyramid, a prism, a cone, a pillar, or a protrusion;

Methods, systems, and devices related to counter-based sense amplifier method for memory cells are described. The counter-based read algorithm may comprise the following phases: storing in a counter associated to an array of memory cells the value of the number of bits having a predetermined logic value of the data bits stored in the memory array; reading from said counter the value corresponding to the number of bits having the predetermined logic value; reading the data stored in the array of memory cells by applying a ramp of biasing voltages; counting the number of bits having the predetermined logic value during the data reading phase; stopping the data reading phase when the number of bits having the predetermined logic value is equal to the value stored in said counter.

A method of sensing a resistance change memory device includes preparing a memory cell including a variable resistance element storing different data on the basis of a variable resistance, and a switching element connected to the variable resistance element and performing a threshold switching operation, measuring a first cell current by applying a first read voltage to the memory cell, the first read voltage being selected in a threshold-sensing range of a current-voltage characteristic curve of the memory cell, measuring a second cell current by applying a second read voltage to the memory cell, the second read voltage being selected in a resistance-sensing range of the current-voltage characteristic curve, and when at least one of the first cell current and the second cell current is greater than a corresponding reference current, outputting a data signal having a first logic value as data stored in the memory cell.

The present disclosure generally relates to the fabrication of and methods for creating a reversible tri-state memory device which provides both forward and reverse write and read drive to a bi-directional RRAM cell, thus allowing writing in the forward and reverse directions. The memory device, however, utilizes a single transistor “on pitch” which fits between two metal lines traversing the array tile.

The present disclosure generally relates to non-volatile memory arrays and memory devices in which a leakage current through an OTS is utilized to pre-charge a circuit of a memory chip. By running an additional wire on each side of a tile which is orthogonal to, above, or below the X and Y select wires, a high value resistance material, such as an OTS, may be deposited at the intersection. The OTS allows the word line or bit line to be selected without pulling excessive leakage to the select wire from the bias voltage, such as V/2. A thickness of the OTS is adjusted such that the V.sub.t of the OTS is greater than V/2, with margin, and the OTS does not turn on when the OTS is selected. A resistance is created between the V/2 wire and the word line select wire or the bit line select wire.

A three-dimensional (3D) memory device includes a memory cell array, a first sense amplifier and a second sense amplifier. The memory cell array includes lower memory cells respectively arranged in regions where lower word lines intersect with bit lines and upper memory cells respectively arranged in regions where upper word lines intersect with the bit lines. The first sense amplifier is connected to a first lower word line and performs a data sensing operation on a first lower memory cell connected between a first bit line and the first lower word line. The second sense amplifier is connected to a first upper word line and performs a data sensing operation on a first upper memory cell connected between the first bit line and the first upper word line. The data sensing operations of the first and second sense amplifiers are performed in parallel.