A control method to operate a memory device, a control method to operate a memory system and a control system are provided. The control method includes providing a first voltage to a memory device for accessing a memory element of the memory device; obtaining an aging information of the memory device; and providing a second voltage to the memory device according to the aging information, wherein the first voltage and the second voltage are reverse biased voltages.

A nonvolatile memory apparatus performs a plurality of read operations by using a plurality of read voltages. A first read operation is performed by applying a first read voltage to a memory cell. A second read operation is selectively performed based on whether a snap-back of the memory cell occurs during the first read operation. The second read operation is performed by applying a second read voltage having a higher voltage level than the first read voltage to the memory cell.

Disclosed are a method of operating a selector device, a method of operating a nonvolatile memory apparatus to which the selector device is applied, an electronic circuit device including the selector device, and a nonvolatile memory apparatus. The method of operating the selector device controls access to a memory element, and includes providing the selector device including a switching layer and first and second electrodes disposed on both surfaces of the switching layer, which includes an insulator and a metal element, and applying a multi-step voltage pulse to the switching layer via the first and second electrodes to adjust a threshold voltage of the selector device, the multi-step voltage pulse including a threshold voltage control pulse and an operating voltage pulse. The operating voltage pulse has a magnitude for turning on the selector device, and the threshold voltage control pulse has a lower magnitude lower than the operating voltage pulse.

A semiconductor memory cell and arrays of memory cells are provided In at least one embodiment, a memory cell includes a substrate having a top surface, the substrate having a first conductivity type selected from a p-type conductivity type and an n-type conductivity type; a first region having a second conductivity type selected from the p-type and n-type conductivity types, the second conductivity type being different from the first conductivity type, the first region being formed in the substrate and exposed at the top surface; a second region having the second conductivity type, the second region being formed in the substrate, spaced apart from the first region and exposed at the top surface; a buried layer in the substrate below the first and second regions, spaced apart from the first and second regions and having the second conductivity type; a body region formed between the first and second regions and the buried layer, the body region having the first conductivity type; a gate positioned between the first and second regions and above the top surface; and a nonvolatile memory configured to store data upon transfer from the body region.

Techniques for burst memory write operations are disclosed. In the illustrative embodiment, a memory die is limited in how quickly it can perform memory write operations that it receives from a microcontroller due to thermal constraints. The memory die can mitigate the need for the microcontroller to perform a costly rank switch to send an operation to another die by buffering memory write operations. The microcontroller can then send several consecutive memory write operations to a first memory die before switching to a second memory die. The first memory die can then perform the memory write operations while the microcontroller has moved on to other memory operations.

A read technique for both SLC (single level cell) and MLC (multi-level cell) cross-point memory can mitigate drift-related errors with minimal or no drift tracking. In one example, a read at a higher magnitude voltage is applied first, which causes the drift for cells in a lower threshold voltage state to be reset. In one example, the read at the first voltage can be a full float read to minimize disturb. A second read can then be performed at a lower voltage without the need to adjust the read voltage due to drift.

According to one embodiment, a memory device includes a first wiring line, a second wiring line, a memory cell connected between the first and second wiring lines, including a resistance change memory element having first and second resistance states, and a two-terminal switching element connected in series to the resistance change memory element, and a voltage application circuit which applies a write voltage signal having a first polarity and setting a desired resistance state to the resistance change memory element, to the memory cell, and applies, after the write voltage signal is applied to the memory cell, a second polarity voltage signal having a magnitude that prevents the two-terminal switching element from being set to the on-state, to the memory cell.

Technologies relating to increasing the surface area of selectors in crossbar array circuits are provided. An example apparatus includes: a substrate; a first line electrode formed on the substrate; an RRAM stack formed on the first line electrode, wherein the RRAM stack; an isolation layer formed beside the RRAM stack, wherein the isolation layer includes an upper surface and a sidewall, and a height from the upper surface to the first line electrode is 100 nanometers to 10 micrometers; a selector stack formed on the RRAM stack, the sidewall, and the upper surface; and a second line electrode formed on the selector stack.

A memory device includes a memory cell array including memory cells connected to word lines and bit lines. Each of the memory cells includes a switch element and a memory element, and has a first state or a second state in which a threshold voltage is within a first voltage range or a second voltage range, lower than the first voltage range. A memory controller is configured to execute a first read operation for the memory cells using a first read voltage, higher than a median value of the first voltage range, program first defect memory cells turned off during the first read operation to the first state, execute a second read operation for the memory cells using a second read voltage, lower than a median value of the second voltage range, and execute a repair operation for second defect memory cells turned on during the second read operation.

A memory circuit configured to perform multiply-accumulate (MAC) operations for performance of an artificial neural network includes a series of synapse cells arranged in a cross-bar array. Each cell includes a memory transistor connected in series with a memristor. The memory circuit also includes input lines connected to the source terminal of the memory transistor in each cell, output lines connected to an output terminal of the memristor in each cell, and programming lines coupled to a gate terminal of the memory transistor in each cell. The memristor of each cell is configured to store a conductance value representative of a synaptic weight of a synapse connected to a neuron in the artificial neural network, and the memory transistor of each cell is configured to store a threshold voltage representative of a synaptic importance value of the synapse connected to the neuron in the artificial neural network.