An integrated circuit memory device having: a memory cell; a current sensor connected to the memory cell; a voltage driver connected to the memory cell; and a bleed circuit connected to the voltage driver. During an operation to read the memory cell, the voltage driver drives a voltage applied on the memory cell. The bleed circuit is activated to reduce the voltage during a time period in which the current sensor operates to determine whether or not at least a predetermined level of current is presented in the memory cell.

A memory device can include a plurality of memory cells including a first group of memory cells and a second group of memory cells programmed to a predefined logic state. The plurality of memory cells includes a memory controller configured to apply a reading voltage to at least one selected memory cell of the first group during a reading operation, apply the reading voltage to the memory cells of the second group, and responsive to the logic state of at least one memory cell of the second group being assessed to be different from the predefined logic state perform a refresh operation of the memory cells of the first group by applying a recovery voltage higher than the reading voltage to assess the logic state thereof and reprogramming the memory cells of the first group to the logic state assessed with the recovery voltage.

A system may include multiple memory cells to store logical data, age tracking circuitry to track a time since a previous access of a particular memory cell, and control circuitry to access the memory cell. Such access may include a read operation of the memory cell, a write operation to the memory cell, or both. The control circuitry may determine an electrical parameter of the memory cell based at least in part on the tracked time since the previous access of the memory cell.

Provided herein may be a method of operating a semiconductor device including memory cells each storing multi-bit data. The method includes receiving data that is to be programmed in a memory cell selected from the memory cells; and applying a program pulse to the selected memory cell, the program pulse being determined depending on a logic state of the data and being selected from a group including a first program pulse having a positive polarity, a second program pulse having the positive polarity and having at least one of a peak level, a peak period, and a falling slew rate different from those of the first program pulse, a third program pulse having a negative polarity, and a fourth program pulse having the negative polarity and having at least one of a peak level, a peak period, and a rising slew rate different from those of the third program pulse.

Systems, methods, and apparatus related to dynamically determining read voltages used in memory devices. In one approach, a memory device has a memory array including memory cells. One or more resistors are formed as part of the memory array. A memory controller increments a counter as write operations are performed on the memory cells. When the counter reaches a limit, a write operation is performed on the resistors. The write operation applies voltages to the resistors similarly as applied to the memory cells over time during normal operation. When performing a read operation, a current is applied to one or more of the resistors to determine a boost voltage. When reading the memory cells, a read voltage is adjusted based on the boost voltage. The memory cells are read using the adjusted read voltage.

Systems, methods, and apparatus related to dynamically determining read voltages used in memory devices. In one approach, a memory device has a memory array including memory cells. One or more resistors are formed as part of the memory array. A memory controller increments a counter as write operations are performed on the memory cells. When the counter reaches a limit, a write operation is performed on the resistors. The write operation applies voltages to the resistors similarly as applied to the memory cells over time during normal operation. When performing a read operation, a current is applied to one or more of the resistors to determine a boost voltage. When reading the memory cells, a read voltage is adjusted based on the boost voltage. The memory cells are read using the adjusted read voltage.

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 system may include multiple memory cells to store logical data, age tracking circuitry to track a time since a previous access of a particular memory cell, and control circuitry to access the memory cell. Such access may include a read operation of the memory cell, a write operation to the memory cell, or both. The control circuitry may determine an electrical parameter of the memory cell based at least in part on the tracked time since the previous access of the memory cell.

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.

Methods, circuits, and systems for reading memory cells are described. The method may include: applying a first voltage with a first polarity to a plurality of the memory cells; applying a second voltage with a second polarity to one or more of said plurality of the memory cells; applying at least a third voltage with the first polarity to one or more of said plurality of the memory cells; detecting electrical responses of memory cells to the first voltage, the second voltage, and the third voltage; and determining a logic state of respective memory cells based on the electrical responses of the memory cells to the first voltage, the second voltage, and the third voltage.