A semiconductor memory device disposed over a substrate includes a common electrode, a selector material layer surrounding the common electrode, and a plurality of phase change material layers in contact with the selector material layer.

Exemplary semiconductor structures for neuromorphic applications may include a first layer overlying a substrate material. The first layer may be or include a first oxide material. The structures may include a second layer disposed adjacent the first layer. The second layer may be or include a second oxide material. The structures may also include an electrode material deposited overlying the second layer.

Phase change memory devices and methods of forming the same include forming a fin structure from a first material. A phase change memory cell is formed around the fin structure, using a phase change material that includes two solid state phases at an operational temperature.

An optical synapse comprises a memristive device for non-volatile storage of a synaptic weight dependent on resistance of the device, and an optical modulator for volatile modulation of optical transmission in a waveguide. The memristive device and optical modulator are connected in control circuitry which is operable, in a write mode, to supply a programming signal to the memristive device to program the synaptic weight and, in a read mode, to supply an electrical signal, dependent on the synaptic weight, to the optical modulator whereby the optical transmission is controlled in a volatile manner in dependence on programmed synaptic weight.

Methods and apparatuses for a cross-point memory array and related fabrication techniques are described. The fabrication techniques described herein may facilitate concurrently building two or more decks of memory cells disposed in a cross-point architecture. Each deck of memory cells may include a plurality of first access lines (e.g., word lines), a plurality of second access lines (e.g., bit lines), and a memory component at each topological intersection of a first access line and a second access line. The fabrication technique may use a pattern of vias formed at a top layer of a composite stack, which may facilitate building a 3D memory array within the composite stack while using a reduced number of processing steps. The fabrication techniques may also be suitable for forming a socket region where the 3D memory array may be coupled with other components of a memory device.

Techniques are provided for accessing two memory cells of a memory tile concurrently. A memory tile may include a plurality of self-selecting memory cells addressable using a row decoder and a column decoder. A memory controller may access a first self-selecting memory cell of the memory tile using a first pulse having a first polarity to the first self-selecting memory cell. The memory controller may also access a second self-selecting memory cell of the memory tile concurrently with accessing the first self-selecting memory cell using a second pulse having a second polarity different than the first polarity. The memory controller may determine characteristics of the pulses to mitigate disturbances of unselected self-selecting memory cells of the memory tile.

Methods, systems, and devices for a modified write voltage for memory devices are described. In an example, the memory device may determine a first set of memory cells to be switched from a first logic state (e.g., a SET state) to a second logic state (e.g., a RESET state) based on a received write command. The memory device may perform a read operation to determine a subset of the first set of memory cells (e.g., a second set of memory cells) having a conductance threshold satisfying a criteria based on a predicted drift of the memory cells. The memory device may apply a RESET pulse to each of the memory cells within the first set of memory cells, where the RESET pulse applied to the second set of memory cells is modified to decrease voltage threshold drift in the RESET state.

The present disclosure includes apparatuses, methods, and systems for increase of a sense current in memory. An embodiment includes a memory having a plurality of memory cells, and circuitry configured to count a number of program operations performed on the memory cells of the memory during operation of the memory, and increase a magnitude of a current used to sense a data state of the memory cells of the memory upon the count of the number of program operations reaching a threshold count.

The present disclosure includes apparatuses and methods for programming memory cells using asymmetric current pulses. An embodiment includes a memory having a plurality of self-selecting memory cells, and circuitry configured to program a self-selecting memory cell of the memory by applying a first current pulse or a second current pulse to the self-selecting memory cell, wherein the first current pulse is applied for a longer amount of time than the second current pulse and the first current pulse has a lower amplitude than the second current pulse.

The present disclosure relates to a method for accessing an array of memory cells, including storing a set of user data in a plurality of memory cells, storing, in a portion of the array, additional information representative of a voltage difference between a first threshold voltage and a second threshold voltage of the memory cells programmed to a first logic state, applying to the array a read voltage to activate a first group of memory cells corresponding to a preset number of memory cells, determining that the first group of memory cells has been activated based on applying the read voltage, wherein the read voltage is equal to the first threshold voltage when the first group of memory cells has been activated, and based on the additional data information, applying the voltage difference to the array to activate a second group of memory cells programmed to the first logic state.