Abstract: An operation method for a memory device is provided. The memory device includes a two-terminal selector and a resistance variable storage element coupled to the two-terminal selector. The method includes providing a voltage pulse to the memory device. A voltage applied across the two-terminal selector during a falling part of the voltage pulse falls below a holding voltage of the two-terminal selector. A voltage falling rate of the falling part at which the voltage applied across the two-terminal selector reaches the holding voltage is raised for reducing threshold voltage drift of the two-terminal selector.

Abstract: First fire operations for an ovonic threshold switch (OTS) selector is provided. A first fire operation includes setting a peak amplitude of a voltage pulse, and performing at least one cycle, including: providing the voltage pulse to the OTS selector; sensing an output current passing through the OTS selector in response to the received voltage pulse; comparing a peak amplitude of the voltage pulse with a maximum peak amplitude ensuring initialization of the OTS selector; ending the first fire operation if the peak amplitude reaches the maximum peak amplitude; comparing the output current with a target current indicative of initialization of the OTS selector if the peak amplitude is lower than the maximum peak amplitude; ending the first fire operation if the output current reaches the target current; and setting another voltage pulse with a greater peak amplitude if the output current is lower than the target current.

Abstract: A memory device includes a substrate, a bottom electrode disposed over the substrate, a memory layer disposed over the bottom electrode, a selector layer disposed over the memory layer, and a top electrode disposed over the selector layer. The selector layer is an oxygen-doped chalcogenide based film, and an oxygen content of the selector layer is about 10 at % or less.

Abstract: A memory device is provided. The memory device includes memory cells. Each of the memory cells includes: a resistance variable storage device; and a selector. The selector is stacked with the resistance variable storage device and coupled to the resistance variable storage device with a shared terminal, and includes a switching layer formed of a chalcogenide compound. A thickness of the switching layer is equal to or less than about 5 nm.

Abstract: First fire operations for an ovonic threshold switch (OTS) selector is provided. A first fire operation includes setting a peak amplitude of a voltage pulse, and performing at least one cycle, including: providing the voltage pulse to the OTS selector; sensing an output current passing through the OTS selector in response to the received voltage pulse; comparing a peak amplitude of the voltage pulse with a maximum peak amplitude ensuring initialization of the OTS selector; ending the first fire operation if the peak amplitude reaches the maximum peak amplitude; comparing the output current with a target current indicative of initialization of the OTS selector if the peak amplitude is lower than the maximum peak amplitude; ending the first fire operation if the output current reaches the target current; and setting another voltage pulse with a greater peak amplitude if the output current is lower than the target current.

Abstract: Embodiments include a method of forming a cross-point memory device, the method and device forming a multi-layered selector material. A first level of the multi-layered selector structure may include a subset of the elements of a second level of the multi-tiered selector structure. A gradient concentration of the switching elements may be found in the selector structure, first level including a substantially steady concentration of elements and the second level including a gradient of concentration for the elements in common as well as the elements unique to the first level.

Abstract: A method includes applying a first voltage pulse across a memory cell, wherein the memory cell includes a selector, wherein the first voltage pulse switches the selector into an on-state; after applying the first voltage pulse, applying a second voltage pulse across the memory cell, wherein before applying the second voltage pulse the selector has a first voltage threshold, wherein after applying the second voltage pulse the selector has a second voltage threshold that is less than the first voltage threshold; and after applying the second voltage pulse, applying a third voltage pulse across the memory cell, wherein the third voltage pulse switches the selector into an on-state; wherein the selector remains continuously in an off-state between the first voltage pulse and the third voltage pulse.

Abstract: A random number generator that includes control circuit, an oscillation circuit, an oscillation detection circuit and a latch circuit is introduced. The control circuit sweeps a configuration of a bias control signal among a plurality of configurations. The oscillation circuit generates an oscillation signal based on the configuration of the bias control signal. The oscillation detection circuit detects an onset of the oscillation signal, and outputs a lock signal. The latch circuit latches the oscillation signal according to a trigger signal to output a random number, wherein the trigger signal is asserted after the lock signal is outputted, and the configuration of bias control signal is locked after the lock signal is outputted. A method for generating a random number and an operation method of a random number generator are also introduced.

Abstract: An operation method for a memory device is provided. The memory device includes a two-terminal selector and a resistance variable storage element coupled to the two-terminal selector. The method includes providing a voltage pulse to the memory device. A voltage applied across the two-terminal selector during a falling part of the voltage pulse falls below a holding voltage of the two-terminal selector. A voltage falling rate of the falling part at which the voltage applied across the two-terminal selector reaches the holding voltage is raised for reducing threshold voltage drift of the two-terminal selector.

Abstract: An ovonic threshold switch (OTS) selector and a memory device including the OTS selector is provided. The OTS selector includes a switching layer formed of a GeCTe compound further doped with one or both of nitrogen and silicon, and exhibits improved thermal stability and electrical performance.

Abstract: A random number generator that includes control circuit, an oscillation circuit, an oscillation detection circuit and a latch circuit is introduced. The control circuit sweeps a configuration of a bias control signal among a plurality of configurations. The oscillation circuit generates an oscillation signal based on the configuration of the bias control signal. The oscillation detection circuit detects an onset of the oscillation signal, and outputs a lock signal. The latch circuit latches the oscillation signal according to a trigger signal to output a random number, wherein the trigger signal is asserted after the lock signal is outputted, and the configuration of bias control signal is locked after the lock signal is outputted. A method for generating a random number and an operation method of a random number generator are also introduced.

Abstract: A random number generator that includes control circuit, an oscillation circuit, a dynamic header circuit, an oscillation detection circuit and a latch circuit is introduced. The control circuit sweeps a configuration of a bias control signal among a plurality of configurations. The dynamic header circuit generates a bias voltage based on the configuration of the bias control signal. The oscillation circuit generates an oscillation signal based on the bias voltage. The oscillation detection circuit detects an onset of the oscillation signal, and outputs a lock signal. The latch circuit latches the oscillation signal according to a trigger signal to output a random number, wherein the trigger signal is asserted after the lock signal is outputted, and the configuration of bias control signal is locked after the lock signal is outputted. A method for generating a random number and an operation method of a random number generator are also introduced.