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.

Provided herein may be a resistive memory device and a method of operating the resistive memory device. The resistive memory device may include strings coupled between one or more source lines and one or more bit lines, each string including a set of one or more resistive memory cells, one or more word lines respectively coupled to the set of one or more resistive memory cells; and a voltage generator configured to control a level of a turn-on voltage to be applied to one or more unselected word lines among the one or more word lines depending on a program target state of a subset of resistive memory cells including one or more resistive memory cells selected from among the set of one or more resistive memory cells.

Technologies relating to CMOS image sensors with integrated Resistive Random-Access Memory (RRAMs) units that provide energy efficient analog storage, ultra-high speed analog storage, and in-memory computing functions are disclosed. An example CMOS image sensor with integrated RRAM crossbar array circuit includes a CMOS image sensor having multiple pixels configured to receive image signals; a column decoder configured to select the pixels in columns to read out; a row decoder configured to select the pixels in rows to read out; an amplifier configured to amplify first signals received from the CMOS image sensor; a multiplexer configured to sequentially or serially read out second signals received from the amplifier; and a first RRAM crossbar array circuit configured to store third signals received from the multiplexer.

Methods and systems include memory devices with a memory array comprising a plurality of memory cells. The memory devices include a control circuit operatively coupled to the memory array and configured to receive a read request for data and to apply a first voltage to the memory array based on the read request. The control circuit is additionally configured to count a total number of the plurality of memory cells that have switched to an active read state based on the first voltage and to apply a second voltage to the memory array based on the total number. The control circuit is further configured to return the data based at least on bits stored in a first and a second set of the plurality of memory cells.

A memory device is provided that includes at least one resistive memory cell, a negative capacitance field effect transistor (NC-FET) serving as a voltage amplifier, and a switch enable circuit connecting NC-FET to the memory cell. The NC-FET includes a regular FET having a metal gate terminal and a ferroelectric capacitor. The NC-FET gate terminal forms one plate of the ferroelectric (FE) capacitor. The ferroelectric capacitor includes a ferroelectric dielectric material deposited between a formed upper gate conductive contact and he metal gate terminal. To provide further flexibility, a metal layer can be deposited before the deposition of the ferroelectric material to form a MIM-like FE capacitor so that the capacitance of FE capacitance can be independently tuned by choosing the right height (H), width (W), and length (L) to achieve desired matching between |C.sub.FE| and C.sub.ox where C.sub.ox is the gate oxide capacitance and C.sub.FE is the ferroelectric capacitance.

Provided are memory devices and memory systems. The memory device includes a memory cell array in a first semiconductor layer and including word lines stacked in a first direction, and channel structures passing through the word lines in the first direction; a control logic circuit in a second semiconductor layer located below the first semiconductor layer in the first direction; and a physical unclonable function (PUF) circuit including a plurality of through electrodes passing through the first semiconductor layer and the second semiconductor layer, and configured to generate PUF data according to resistance values of the plurality of through electrodes, and generate the PUF data based on a node voltage between through electrodes connected in series, among the plurality of through electrodes.

Embodiments of the present invention include a memory cell that has a vertically-oriented fin. The memory cell may also include a resistive memory device located on a first lateral side of the fin. The resistive memory device may include a bottom electrode, a top electrode, and a resistive element between the bottom electrode and the top electrode. The memory cell may also include a vertical field-effect transistor having a metal gate and a gate dielectric contacting a second lateral side of the fin opposite the first lateral side.

An integrated circuit memory device having: a memory cell; and a voltage driver of depletion type connected to the memory cell. In a first polarity, the voltage driver is powered by a negative voltage relative to ground to drive a negative selection voltage or a first de-selection voltage; In a second polarity, the voltage driver is powered by a positive voltage relative to ground to drive a positive selection voltage or a second de-selection voltage. The voltage driver is configured to transition between the first polarity and the second polarity. During the transition, the voltage driver is configured to have a control voltage swing for outputting de-selection voltages smaller than a control voltage swing for output selection voltages.

Systems, methods and apparatus to program a memory cell to have a threshold voltage to a level representative of one value among more than two predetermined values. A first voltage pulse is driven across the memory cell to cause a predetermined current to go through the memory cell. The first voltage pulse is sufficient to program the memory cell to a level representative of a first value. To program the memory cell to a level representative of a second value, a second voltage pulse, different from the first voltage pulse, is driven across the memory cell within a time period of residual poling in the memory cell caused by the first voltage pulse.

Systems, methods and apparatus to program memory cells to an intermediate state. A first voltage pulse is applied in a first polarity across each respective memory cell among the memory cells to move its threshold voltage in the first polarity to a first voltage region representative of a first value. A second voltage pulse is then applied in a second polarity to further move its threshold voltage in the first polarity to a second voltage region representative of a second value and the intermediate state. A magnitude of the second voltage pulse applied for the memory cells is controlled by increasing the magnitude in increments until the memory cells are sensed to be conductive. Optionally, prior to the first voltage pulse, a third voltage pulse is applied in the second polarity to cancel or reduce a drift in threshold voltages of the respective memory cell.