According to embodiments, a semiconductor memory device includes a first electrode, a second electrode, a memory cell, and a control circuit. The memory cell is provided between the first electrode and the second electrode and includes a metal film and a resistance change film. The control circuit applies a voltage between the first electrode and the second electrode to perform transition of a resistive state of the memory cell. The control circuit performs a first writing operation by applying a first pulse having a voltage of a first polarity to the memory cell and applying a second pulse having a voltage of the first polarity smaller than the voltage of the first pulse to the memory cell continuously after applying the first pulse.

According to one embodiment, a semiconductor memory device includes a first electrode, a second electrode, a memory cell, and a control circuit. The memory cell is provided between the first electrode and the second electrode, and includes a metal film and a resistance change film. The control circuit applies a voltage between the first electrode and the second electrode to transition a resistive state of the memory cell. The control circuit performs a first reset operation by applying a first pulse having a voltage of a first polarity to the memory cell, and applying a second pulse having a voltage of a second polarity that is an inverse of the first polarity to the memory cell after applying the first pulse.

Embodiments of the invention are directed to a resistive switching device (RSD). A non-limiting example of the RSD includes a fin-shaped element formed on a substrate, wherein the fin-shaped element includes a source region, a central channel region, and a drain region. A gate is formed over a top surface and sidewalls of the central channel region. The fin-shaped element is doped with impurities that generate interstitial charged particles configured to move interstitially through a lattice structure of the fin-shaped element under the influence of an electric field applied to the RSD.

An enhanced ferroelectric transistor may include Interface switching modulation (ISM) layers along with a ferroelectric layer in the gate of the transistor to increase a memory window while maintaining relatively low operating voltages. The enhanced ferroelectric transistor may be implemented as a memory device storing more than two bits of information in each memory cell. An enhanced ferroelectric tunnel junction device may include ISM layers and a ferroelectric layer to amplify the tunneling barriers in the device. The ISM layers may form material dipoles that add to the effect of ferroelectric dipoles in the ferroelectric material.

The present invention discloses a multi-bit-per-cell three-dimensional resistive random-access memory (3D-RRAM.sub.MB). It comprises a plurality of RRAM cells stacked above a semiconductor substrate. Each RRAM cell comprises a RRAM layer, which is switched from a high-resistance state to a low-resistance state during programming. By adjusting the programming current, the programmed RRAMs have different resistances.

A memory device according to an embodiment includes a first interconnect, a second interconnect, a first variable resistance member, a third interconnect, a second variable resistance member, a fourth interconnect, a fifth interconnect and a third variable resistance member. The first interconnect, the third interconnect and the fourth interconnect extend in a first direction. The second interconnect and the fifth interconnect extend in a second direction crossing the first direction. The first variable resistance member is connected between the first interconnect and the second interconnect. The second variable resistance member is connected between the second interconnect and the third interconnect. The third variable resistance member is connected between the fourth interconnect and the fifth interconnect. The fourth interconnect is insulated from the third interconnect.

Techniques are provided for programming a self-selecting memory cell that stores a first logic state. To program the memory cell, a pulse having a first polarity may be applied to the cell, which may result in the memory cell having a reduced threshold voltage. During a duration in which the threshold voltage of the memory cell may be reduced (e.g., during a selection time), a second pulse having a second polarity (e.g., a different polarity) may be applied to the memory cell. Applying the second pulse to the memory cell may result in the memory cell storing a second logic state different than the first logic state.

There are provided a variable resistance memory device and a manufacturing method of the same. The variable resistance memory device includes: a first electrode; a second electrode arranged in a vertical direction from the first electrode; and an oxide layer having an oxygen deficient region extending in the vertical direction between the second electrode and the first electrode.

A resistive random-access memory (ReRAM) cell formed on a silicon over insulator substrate (SOI) is provided. The ReRAM includes a SOI substrate, a first MOSFET and a second MOSFET, each of which having a drain port, a gate port, a source port, and a bulk port. The drain port of the second MOSFET is connected to the source port of the first MOSFET; a first resistive element and a second resistive element, each having a first port and a second port, wherein the first ports of both resistive elements are connected to the drain of the first MOSFET; a first word line and a second word line connected to the gate port of the first MOSFET and the second MOSFET, respectively; and the state of the ReRAM cell is determined upon applying a predefined potential.

A memory device according to an embodiment includes a memory cell array, first and second memory cells, first and second read circuit, and first and second write circuit. The memory cell array includes first and second sub-arrays. The first memory cells is included in each of the first sub-arrays. The second memory cells is included in each of the second sub-arrays. The first and second read circuit are provided for reading data of the first and second memory cells, respectively. The first and second write circuit are provided for writing data to the first and second memory cells, respectively. An area of the first sub-array is different from an area of the second sub-array.