A semiconductor memory includes first to third lines, the second line crossing the first and third lines between the first line and the third line, a first memory element overlapping an intersection region of the first and second lines between the first line and the second line, the first memory element including a first memory layer, a first electrode under the first memory layer, and a second electrode over the first memory layer, and a second memory element overlapping an intersection region of the second and third lines between the second line and the third line, the second memory element including a second memory layer, a third electrode under the second memory layer, and a fourth electrode over the second memory layer. An electrical resistance relation of the third and fourth electrodes is controlled according to an electrical resistance relation of electrical resistances of the first and second electrodes.

Systems, methods and apparatus of implementing spiking neural networks. For example, an integrated circuit includes a crossbar array of first memristors connected between wordlines and bitlines. The first memristors are configured to convert voltages applied on the wordlines into currents in the bitlines. Second memristors having thresholds are connected to the bitlines respectively. Each respective memristor in the second memristors can reduce its resistance to cause spiking in a current flowing through the respective memristor, when the current reaches the threshold of the respective memristor. Current level detectors are connected to the second memristors to determine whether the currents in the bitlines have levels corresponding to reaching thresholds of the second memristors and thus, generate output spikes of spiking neurons without using analog-to-digital converters to measure the currents in the bitlines.

Devices and methods for determining resistive states of resistive change elements in resistive change element arrays are disclosed. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements by sensing current flow. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements without the need for in situ selection devices or other current controlling devices. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can reduce the impact of sneak current when determining resistive states of resistive change elements.

A low read current architecture for memory. Bit lines of a cross point memory array are allowed to be charged by a selected word line until a minimum voltage differential between a memory state and a reference level is assured.

A data storage circuit includes a matrix array of memory cells. The memory cells are configurable and non-volatile. Each one is intended to operate in either one of two operating configurations; the first operating configuration corresponding to a ferroelectric random-access memory; and the second operating configuration corresponding to a metal-oxide resistive random-access memory. Each memory cell comprises: a stack of thin layers in the following order: a first layer made of an electrically conductive material forming a lower electrode, a second layer made of a dielectric and ferroelectric material and a third layer made of electrically conductive material forming an upper electrode.

A phase change memory includes a phase change structure. There is a heater coupled to a first surface of the phase change structure. A first electrode is coupled to a second surface of the phase change structure. A second electrode coupled to a second surface of the heater. A third electrode is connected to a first lateral end of the phase change structure and a fourth electrode connected to a second lateral end of the phase change structure.

A memory using mixed valence conductive oxides is disclosed. The memory includes a mixed valence conductive oxide that is less conductive in its oxygen deficient state and a mixed electronic ionic conductor that is an electrolyte to oxygen and promotes an electric field effective to cause oxygen ionic motion.

Methods for precharging bit lines using closed-loop feedback are described. In one embodiment, a sense amplifier may include a bit line precharge circuit for setting a bit line to a read voltage prior to sensing a memory cell connected to the bit line. The bit line precharge circuit may include a first transistor in a source-follower configuration with a first gate and a first source node electrically coupled to the bit line. By applying local feedback from the first source node to the first gate, the bit line settling time may be reduced. In some cases, a first voltage applied to the first gate may be determined based on a first current drawn from the first bit line. Thus, the first voltage applied to the first gate may vary over time depending on the conductivity of a selected memory cell connected to the bit line.

Resistive memory devices are provided which are configured to mitigate resistance drift. A device comprises a phase-change element, a resistive liner, a first electrode, a second electrode, and a third electrode. The resistive liner is disposed in contact with a first surface of the phase-change element. The first electrode is coupled to a first end portion of the resistive liner. The second electrode is coupled to a second end portion of the resistive liner. The third electrode is coupled to the first surface of the phase-change element.

Devices and methods for accessing resistive change elements in a resistive change element array to determine resistive states of the resistive change elements are disclosed. According to some aspects of the present disclosure the devices and methods access resistive change elements in a resistive change element array through a variety of operations. According to some aspects of the present disclosure the devices and methods supply an amount of current tailored for a particular operation. According to some aspects of the present disclosure the devices and methods compensate for circuit conditions of a resistive change element array by adjusting an amount of current tailored for a particular operation to compensate for circuit conditions of the resistive change element array.