Methods, systems, and devices for multi-component cell architectures for a memory device are described. A memory device may include self-selecting memory cells that include multiple self-selecting memory components (e.g., multiple layers or other segments of a self-selecting memory material, separated by electrodes). The multiple self-selecting memory components may be configured to collectively store one logic state based on the polarity of a programming pulse applied to the memory cell. The multiple memory component layers may be collectively (concurrently) programmed and read. The multiple self-selecting memory components may increase the size of a read window of the memory cell when compared to a memory cell with a single self-selecting memory component. The read window for the memory cell may correspond to the sum of the read windows of each self-selecting memory component.

A phase change memory (PCM) structure configured for performing a gradual reset operation includes first and second electrodes and a phase change material layer disposed between the first and second electrodes. The PCM structure further includes a thermal insulation layer disposed on at least sidewalls of the first and second electrodes and phase change material layer. The thermal insulation layer is configured to provide non-uniform heating of the phase change material layer. Optionally, the thermal insulation layer may be formed as an air gap. The PCM structure may be configured having the first and second electrodes aligned in a vertical or a lateral arrangement.

A memory device includes a memory cell array including a select transistor and a plurality of memory cells connected in series, each memory cell including a cell transistor and a variable resistance layer connected in parallel. During a write operation, a voltage setting circuit is controlled to apply a first voltage to a selected word line and a second voltage to non-selected word lines. The time period for applying the first voltage to the selected word line starts later than the time period for applying the second voltage to the non-selected word lines and ends earlier than the time period for applying the second voltage to the non-selected word lines.

In one embodiment, a state is encoded into a memory cell comprising a phase change material (PM) region and a select device (SD) region by: applying a first current in the memory cell over a first time period, wherein the first current applied over the first time period causes the PM region of the memory cell to be placed into an amorphous state and the SD region of the memory cell to be placed into an amorphous state; and applying a second current in the memory cell over a second time period after the first time period, wherein the second current applied over the third time period causes the SD region of the memory cell to be placed into a crystalline state and the PM region of the memory cell to remain in the amorphous state.

A semiconductor device may include first row lines each extending in a first direction, column lines each extending in a second direction crossing the first direction, second row lines each extending in the first direction, a plurality of first memory cells respectively coupled between the first row lines and the column lines, each of the plurality of first memory cells including a first variable resistance layer and a first dielectric layer positioned between the first variable resistance layer and a corresponding one of the first row lines, and a plurality of second memory cells respectively coupled between the second row lines and the column lines, each of the plurality of second memory cells including a second variable resistance layer and a second dielectric layer positioned between the second variable resistance layer and a corresponding one of the second row lines.

A projected memory device includes a carbon-based projection component. The device includes two electrodes, a memory segment, and a projection component. The projection component and the memory segment form a dual element that connects the two electrodes. The projection component extends parallel to and in contact with the memory segment. The memory segment includes a resistive memory material, while the projection component includes a thin film of non-insulating material that essentially comprises carbon. In a particular implementation, the non-insulating material and the projection component essentially comprises amorphous carbon. Using carbon and, in particular, amorphous carbon, as a main component of the projection component, allows unprecedented flexibility to be achieved when tuning the electrical resistance of the projection component.

Systems, methods and apparatus to program memory cells to an intermediate state. A first voltage pulse is applied in a first polarity across each respective memory cell among the memory cells to move its threshold voltage in the first polarity to a first voltage region representative of a first value. A second voltage pulse is then applied in a second polarity to further move its threshold voltage in the first polarity to a second voltage region representative of a second value and the intermediate state. A magnitude of the second voltage pulse applied for the memory cells is controlled by increasing the magnitude in increments until the memory cells are sensed to be conductive. Optionally, prior to the first voltage pulse, a third voltage pulse is applied in the second polarity to cancel or reduce a drift in threshold voltages of the respective memory cell.

A memory device includes: a memory cell array comprising a plurality of memory cells; a temperature sensor configured to detect a temperature of the memory cell array; a write circuit configured to write data into the plurality of memory cells; and a controller coupled to the temperature sensor and the write circuit, wherein the controller is configured to determine a target write pulse width used by the write circuit based on the detected temperature of the memory device.

A resistive random-access memory (RRAM) circuit includes an RRAM device configured to output a cell current responsive to a bit line voltage, and a current limiter including an input terminal coupled to the RRAM device, first and second parallel current paths configured to conduct the cell current between the input terminal and a reference voltage node, and an amplifier configured to generate a first signal responsive to a voltage level at the input terminal and a reference voltage level. Each of the first and second current paths includes a switching device configured to selectively conduct a portion of the cell current responsive to the first signal.

A neuron circuit and an artificial neural network chip are provided. The neuron circuit includes a memristor and an integrator. The memristor generates a pulse train having an oscillation frequency when an applied voltage exceeds a predetermined threshold. The integrator is connected in parallel to the memristor for receiving and accumulating input pulses transmitted by a previous layer network at different times, and driving the memristor to transmit the pulse train to a next layer network when a voltage of the accumulated input pulses exceeds the predetermined threshold.