Abstract: Methods, apparatuses and systems related to reading data from memory cells configured to store more than one bit are described. The apparatus may be configured to determine a polarity data associated with reading data stored at a target location. In reading the data stored at the target location, the apparatus may apply one or more voltage levels across different polarities according to the determined polarity data.

Abstract: A single memory chip including both memory and storage capabilities on the single chip and accompanying process for forming a memory array including both capabilities is disclosed. In particular, the single chip may incorporate the use of two different chalcogenide materials deposited thereon to implement the memory and storage capabilities. Chalcogenide materials provide flexibility on cell performance, such as by changing the chalcogenide material composition. For the single memory chip, one type of chalcogenide material may be utilized to create memory cells and another type of chalcogenide material may be utilized to create storage cells. The process for forming the memory array includes forming first and second openings in a starting structure and performing a series of etching and deposition steps on the structure to form the memory and storage cells using the two different chalcogenide compositions. The memory and storage cells are independently addressable via wordline and bitline selection.

Abstract: Methods, systems, and devices for adaptive write operations for a memory device are described. In an example, the described techniques may include identifying a quantity of access operations performed on a memory array, modifying one or more parameters for a write operation based on the identified quantity of access operations, and writing logic states to the memory array by performing the write operation according to the one or more modified parameters. In some examples, the memory array may include memory cells associated with a configurable material element, such as a chalcogenide material, that stores a logic state based on a material property of the material element. In some examples, the described techniques may at least partially compensate for a change in memory material properties due to aging or other degradation or changes over time (e.g., due to accumulated access operations).

Abstract: Methods, systems, and devices for varying-polarity read operations for polarity-written memory cells are described. Memory cells may be programmed to store different logic values based on applying write voltages of different polarities to the memory cells. A memory device may read the logic values based on applying read voltages to the memory cells, and the polarity of the read voltages may vary such that at least some read voltages have one polarity and at least some read voltages have another polarity. The read voltage polarity may vary randomly or according to a pattern and may be controlled by the memory device or by a host device for the memory device.

Abstract: An example apparatus can include a memory array and a memory controller. The memory array can include a first portion including a first plurality of memory cells. The memory array can further include a second portion including a second plurality of memory cells. The memory controller can be coupled to the first portion and the second portion. The memory controller can be configured to operate the first plurality of memory cells for short-term memory operations. The memory controller can be further configured to operate the second plurality of memory cells for long-term memory operations.

Abstract: 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.

Abstract: Methods, systems, and devices for random number generation based on threshold voltage randomness are described. For example, a memory device may apply a voltage to a chalcogenide element and increase the applied voltage at least until the applied voltage satisfies a threshold voltage associated with the chalcogenide element. The memory device may detect the state of an oscillating signal at a time at which the applied voltage satisfies the threshold voltage, and the memory device may output a logic value corresponding to the state of the oscillating signal. The threshold voltage of the chalcogenide element may vary in a statistically random manner across voltage applications, and hence the state of the oscillating signal at the time an applied voltage reaches the threshold voltage may likewise vary in a statistically random manner, and thus the corresponding logic value that is output may be a random value suitable for random number generation.

Abstract: Methods and devices based on the use of dopant-modulated etching are described. During fabrication, a memory storage element of a memory cell may be non-uniformly doped with a dopant that affects a subsequent etching rate of the memory storage element. After etching, the memory storage element may have an asymmetric geometry or taper profile corresponding to the non-uniform doping concentration. A multi-deck memory device may also be formed using dopant-modulated etching. Memory storage elements on different memory decks may have different taper profiles and different doping gradients.

Abstract: Methods, systems, and devices for a cross-point pillar architecture for memory arrays are described. Multiple selector devices may be configured to access or activate a pillar within a memory array, where the selector devices may each be or include a chalcogenide material. A pillar access line may be coupled with multiple selector devices, where each selector device may correspond to a pillar associated with the pillar access line. Pillar access lines on top and bottom of the pillars of the memory array may be aligned in a square or rectangle formation, or in a hexagonal formation. Pillars and corresponding selector devices on top and bottom of the pillars may be located at overlapping portions of the pillar access lines, thereby forming a cross point architecture for pillar selection or activation. The selector devices may act in pairs to select or activate a pillar upon application of a respective selection voltage.

Abstract: Systems, methods, and apparatuses are provided for unipolar programming of memory cells in a semiconductor device. A memory has a plurality of self-selecting memory cells and circuitry configured to program a self-selecting memory cell of the plurality of self-selecting memory cells to a first data state or a second data state by applying a current pulse to the self-selecting memory cell. The current is a set pulse or a reset pulse. The set pulse and the reset pulse have a same polarity.

Abstract: 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.

Abstract: Systems, methods, and apparatus related to memory devices (e.g., storage class memory). In one approach, a memory device has a memory array including memory cells arranged as differential memory cell pairs, with each pair storing a single logical bit. The memory device has a controller that receives a command from a host to initiate a read operation. The memory cell pair is selected using bitlines and a common wordline. A partition of the memory array is accessed to read the data stored by the memory cell pair, and then store the read data in a latch for sending to the host. In response to accessing the partition, a counter is incremented. The controller statistically determines whether to perform a refresh operation for the partition based on comparing the current value of the counter to a value previously generated by a random number generator.

Abstract: Methods, systems, devices, and other implementations to store fuse data in memory devices are described. Some implementations may include an array of memory cells with different portions of cells for storing data. A first portion of the array may store fuse data and may contain a chalcogenide storage element, while a second portion of the array may store user data. Sense circuitry may be coupled with the array, and may determine the value of the fuse data using various signaling techniques. In some cases, the sense circuitry may implement differential storage and differential signaling to determine the value of the fuse data stored in the first portion of the array.

Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device includes a memory array. The memory array has first tiles and second tiles. Each of the tiles includes memory cells. Wordlines are configured to select the memory cells in the first and second tiles. A controller programs the selected memory cells by applying a first voltage to a first wordline, and a second voltage to a second wordline. The first and second voltages are applied in a counter-phase manner. The second voltages boosted by charge sharing between the first and second wordlines.

Abstract: Techniques are provided for programming a self-selecting memory cell that stores a first logic state. To program the memory cell, a pulse having a first polarity may be applied to the cell, which may result in the memory cell having a reduced threshold voltage. During a duration in which the threshold voltage of the memory cell may be reduced (e.g., during a selection time), a second pulse having a second polarity (e.g., a different polarity) may be applied to the memory cell. Applying the second pulse to the memory cell may result in the memory cell storing a second logic state different than the first logic state.

Abstract: Methods, systems, and devices for pulse based multi-level cell programming are described. A memory device may identify an intermediate logic state to store to a multi-level memory cell capable of storing three or more logic states. The memory device may apply a first pulse with a first polarity to the memory cell to store a SET or RESET state to the memory cell based on identifying the intermediate logic state. As such, the memory device may identify a threshold voltage of the memory cell that stores the SET or RESET state. The memory device may apply a quantity of pulses to the memory cell to store the identified intermediate logic state based on identifying the threshold voltage of the memory cell that stores the SET or RESET state. In some examples, the quantity of pulses may have a second polarity different than the first polarity.

Abstract: Methods, systems, and devices for improved techniques for multi-level memory cell programming are described. A memory array may receive a first command to store a first logic state in a memory cell for storing three or more logic states. The memory array may apply, as part of an erase operation, a first pulse with a first polarity to a plurality of memory cells to store a second logic state different from the first logic state in the plurality of memory cells, where the plurality of memory cells includes the memory cell. The memory array may apply, as part of a write operation or as part of the erase operation, one or more second pulses with a second polarity to the memory cell to store the first logic state in the memory cell based on applying the first pulse.

Abstract: Methods, systems, and devices for improving write latency and energy using asymmetric cell design are described. A memory device may implement a programming scheme that uses low programming pulses based on an asymmetric memory cell design. For example, the asymmetric memory cells may have electrodes with different contact areas (e.g., widths) and may accordingly be biased to a desired polarity (e.g., negative biased or positive biased) for programming operations. That is, the asymmetric memory cell design may enable an asymmetric read window budget. For example, an asymmetric memory cell may be polarity biased, supporting programming operations for logic states based on the polarity bias.

Abstract: Methods, systems, and devices for asymmetric memory cell design are described. A memory device may implement a programming scheme that uses low programming pulses based on an asymmetric memory cell design. For example, the asymmetric memory cells may have electrodes with different contact areas (e.g., widths) and may accordingly be biased to a desired polarity (e.g., negative biased or positive biased) for programming operations. That is, the asymmetric memory cell design may enable an asymmetric read window budget. For example, an asymmetric memory cell may be polarity biased, supporting programming operations for logic states based on the polarity bias.

Abstract: Methods and devices based on the use of dopant-modulated etching are described. During fabrication, a memory storage element of a memory cell may be non-uniformly doped with a dopant that affects a subsequent etching rate of the memory storage element. After etching, the memory storage element may have an asymmetric geometry or taper profile corresponding to the non-uniform doping concentration. A multi-deck memory device may also be formed using dopant-modulated etching. Memory storage elements on different memory decks may have different taper profiles and different doping gradients.