A memory chip, a memory system, and a method of accessing the memory chip. The memory chip includes a substrate, a first storage unit, and a second storage unit. The first storage unit includes a plurality of first memory cells may have a first storage capacity of 2.sup.n. The plurality of first memory cells may be configured to activate in response to a first selection signal. The second storage unit includes a plurality of second memory cells and may have a second storage capacity of 2.sup.n+1. The plurality of second memory cells may be configured to activate in response to a second selection signal.

A method for operating a neuromorphic memory circuit. The method includes accumulating a dendrite LIF charge over time on a conductive dendrite LIF line. A first transmitting operation transmits an axon LIF pulse on a conductive axon LIF line. A first switching operation switches on a LIF transistor by the axon LIF pulse such that the LIF transistor provides a discharge path for the dendrite LIF charge through a programmable resistive memory element when the axon LIF line transmits the axon LIF pulse. A second transmitting operation transmits a dendrite STDP pulse if the dendrite LIF charge falls below a threshold voltage. A third transmitting operation transmits an axon STDP pulse on a conductive axon STDP line. A second switching operation switches on a STDP transistor by the axon STDP pulse. The STDP transistor provides an electrical path for the dendrite STDP pulse through the programmable resistive memory element when the axon STDP line transmits the axon STDP pulse.

Disclosed herein is a memory cell including a memory element and a selector device. Data may be stored in both the memory element and selector device. The memory cell may be programmed by applying write pulses having different polarities and magnitudes. Different polarities of the write pulses may program different logic states into the selector device. Different magnitudes of the write pulses may program different logic states into the memory element. The memory cell may be read by read pulses all having the same polarity. The logic state of the memory cell may be detected by observing different threshold voltages when the read pulses are applied. The different threshold voltages may be responsive to the different polarities and magnitudes of the write pulses.

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.

Methods, systems, and devices for memory device decoder configurations are described. A memory device may include an array of memory cells and decoder circuits. The array may include one or more memory cells coupled with an access line, and a decoder circuit may be configured to bias the access line to one or more voltages. The decoder circuit may include a first transistor coupled with the access line and a second transistor coupled with the access line. The first transistor may be a planar transistor having a first gate electrode formed on a substrate, and the second transistor may be a trench transistor having a second gate electrode that extends into a cavity of the substrate, where a length of a first gate electrode may be greater than a length of the second gate electrode.

According to one embodiment, a memory device includes a memory cell including a resistance change memory portion and a switching portion, and a voltage applying circuit carrying out, at a time of writing data to the memory cell, an operation of applying a voltage of a first polarity to the memory cell and applying a first voltage to the memory cell, an operation of applying a voltage of a second polarity to the memory cell and applying a second voltage to the memory cell, an operation of applying a voltage of the first polarity to the memory cell and applying a third voltage to the memory cell, or an operation of applying a voltage of the second polarity to the memory cell and applying a fourth voltage to the memory cell.

An embodiment of a semiconductor apparatus may include technology to convert an analog voltage level of a memory cell of a multi-level memory to a multi-bit digital value, and determine a single-bit value of the memory cell based on the multi-bit digital value. Some embodiments may also include technology to track a temporal history of accesses to the memory cell for a duration in excess of ten seconds, and determine the single-bit value of the memory cell based on the multi-bit digital value and the temporal history. Other embodiments are disclosed and claimed.

Two-terminal memory can be set to a first state (e.g., conductive state) in response to a program pulse, or set a second state (e.g., resistive state) in response to an erase pulse. These pulses generally provide a voltage difference between the two terminals of the memory cell. Certain electrical characteristics associated with the pulses can be manipulated in order to enhance the efficacy of the pulse. For example, the pulse can be enhanced or improved to reduce power-consumption associated with the pulse, reduce a number of pulses used to successfully set the state of the memory cell, reduce wear or damage to the memory cell, or to improve Ion or Ioff distribution associated with changing the state of the memory cell.

A variable resistance memory device includes a substrate, a first conductive line on the substrate, the first conductive line extending in a first horizontal direction, a second conductive line extending on the first conductive line in a second horizontal direction perpendicular to the first horizontal direction, and a memory cell at an intersection between the first conductive line and the second conductive line, the memory cell having a selection element layer, an intermediate electrode layer, and a variable resistance layer, and the variable resistance layer having a shape of stairs with a concave center.

In one embodiment, a state is reach from a memory cell comprising a phase change material (PM) region and a select device (SD) region by: ramping a voltage applied to a first address line of an address line pair corresponding to the memory cell until the first address line voltage is stabilized at a predetermined voltage, ramping a voltage applied to a second address line of the address line pair corresponding to the memory cell, detecting a snap in the memory cell while ramping the voltage applied to the second address line, and determining a state of the memory cell based on a differential voltage between the first and second address lines when the memory cell snap occurred.