G11C2013/009

Two-terminal reversibly switchable memory device

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 filed to cause oxygen ionic motion.

Resistive memory

The invention provides a resistive memory with better area efficiency without degrading reliability, which includes an array area, word lines, a local bit line, source lines, and a shared bit line. In the array area, memory cells are arranged in a matrix, and each memory cells includes a variable resistance element and an accessing transistor. The word lines extend in a row direction of the array area and are connected to the memory cells in the row direction. The local bit line extends in a column direction of the array area. The source lines extend in the column direction and are connected to first electrodes of the memory cells in the column direction. The shared bit line is connected to the local bit line. The shared bit line extends in the row direction and is connected to second electrodes of the memory cells in the row direction.

Two memory cells sensed to determine one data value
11670367 · 2023-06-06 · ·

Apparatuses, methods, and systems for sensing two memory cells to determine one data value are described herein. An embodiment includes a memory having a plurality of memory cells and circuitry configured to sense memory states of each of two memory cells to determine one data value. One data value is determined by sensing the memory state of a first one of the two memory cells using a first sensing voltage in a sense window between a first threshold voltage distribution corresponding to a first memory state and a second threshold voltage distribution corresponding to a second memory state and sensing the memory state of a second one of the two memory cells using a second sensing voltage in the sense window. The first and second sensing voltages are selectably closer in the sense window to the first threshold voltage distribution or the second threshold voltage distribution.

Two stage forming of resistive random access memory cells

Provided are memory cells, such as resistive random access memory (ReRAM) cells, each cell having multiple metal oxide layers formed from different oxides, and methods of manipulating and fabricating these cells. Two metal oxides used in the same cell have different dielectric constants, such as silicon oxide and hafnium oxide. The memory cell may include electrodes having different metals. Diffusivity of these metals into interfacing metal oxide layers may be different. Specifically, the lower-k oxide may be less prone to diffusion of the metal from the interfacing electrode than the higher-k oxide. The memory cell may be formed to different stable resistive levels and then resistively switched at these levels. Each level may use a different switching power. The switching level may be selected a user after fabrication of the cell and in, some embodiments, may be changed, for example, after switching the cell at a particular level.

ONE-TIME AND MULTI-TIME PROGRAMING USING A CORRELATED ELECTRON SWITCH

An apparatus including a Correlated Electron Switch (CES) element and a programing circuit is provided. The programing circuit provides a programing signal to the CES element to program the CES element to an impedance state of multiple impedance states when a number of times the CES element has been programed is less than a threshold.

RESISTIVE RANDOM ACCESS MEMORY CELL HAVING BOTTOM-SIDE OEL LAYER AND/OR OPTIMIZED ACCESS SIGNALING

An apparatus is described that includes a resistive random access memory cell having a word line that is to receive a narrowed word line signal that limits an amount of time that an access transistor is on so as to limit the cell's high resistive state and/or the cell's low resistive state. Another apparatus is described that includes a resistive random access memory cell having SL and BL lines that are to receive respective signals having different voltage amplitudes to reduce source degeneration effects of the resistive random access memory cell's access transistor. Another apparatus is described that includes a resistive random access memory cell having a storage cell comprising a bottom-side OEL layer. Another apparatus is described that includes a resistive random access memory cell having a storage cell within a metal layer that resides between a pair of other metal layers where parallel SL and BL lines of the resistive random access memory cell respectively reside.

Reconfigurable Phase Change Device
20170249988 · 2017-08-31 ·

A reconfigurable phase change device with methods for operating and forming the same are disclosed. An example device can comprise a reconfigurable layer comprising a phase change material, and a set of contacts connected with the reconfigurable layer. The set of contacts can comprise at least a first contact, a second contact, and a third contact. The device can comprise at least one control element electrically coupled with one or more of the set of contacts. The at least one control element can be configured to supply a first control signal to one or more of the set of contacts. The first control signal can be configured to modify a first portion of the reconfigurable layer thereby isolating the first contact from the second contact and the third contact.

SENSE AMPLIFIER

Broadly speaking, embodiments of the present techniques provide an amplification circuit comprising a sense amplifier and at least one Correlated Electron Switch (CES) configured to provide a signal to the sense amplifier. The sense amplifier outputs an amplified version of the input signal depending on the signal provided by the CES element. The signal provided by the CES element depends on the state of the CES material. The CES element provides a stable impedance to the sense amplifier, which may improve the reliability of reading data from the bit line, and reduce the number of errors introduced during the reading.

ARRAY DEVICE AND WRITING METHOD THEREOF
20220036947 · 2022-02-03 · ·

An array device and a writing method thereof are provided. A synapse array device includes: a crossbar array, in which a resistive memory element is connected to each intersection of a plurality of row lines and a plurality of column lines; a row select/drive circuit selecting a row line of the crossbar array and applying a pulse signal to the selected row line; a column select/drive circuit selecting a column line of the crossbar array and applying a pulse signal to the selected column line; and a writing part writing to the resistive memory element connected to the selected row line and the selected column line. A first write voltage with controlled pulse width is applied to the selected row line, and a second write voltage with controlled pulse width is applied to the selected column line to perform set writing of the resistive memory element.

APPARATUS AND METHOD FOR CONTROLLING GRADUAL CONDUCTANCE CHANGE IN SYNAPTIC ELEMENT
20220270675 · 2022-08-25 ·

The present invention provides a memory apparatus capable of causing a gradual resistance change for information processing in an analog manner to a synaptic element for implementing a neuromorphic system. To this end, the present invention provides a memory apparatus including: a memory array including a plurality of memory cells capable of selectively storing logic states and a plurality of bit lines and word lines connected to the plurality of memory cells; a controller for controlling a writing step and a reading step; a writing unit; and a reading unit, wherein the controller selects, in the writing step, one or more memory cells from among the plurality of memory cells through the writing unit, sequentially applies a writing voltage thereto to allow the logic states to be written therein, and applies, in the reading step, a reading voltage to the one or more memory cells, which are selected to have the logic states written therein, through the reading unit so as to determine synaptic weights through a sum of currents flowing through the one or more memory cells so that the selected one or more memory cells are allowed to be recognized to operate as one synaptic element.

The present invention also provides a method for determining a synaptic weight in a memory apparatus including a memory array including a plurality of memory cells capable of selectively storing logic states, bit lines and word lines connected to the plurality of memory cells, the method including: (a) selecting one or more memory cells from among the plurality of memory cells, and sequentially applying a writing voltage to write logic states therein; (b) applying a reading voltage to the one or more memory cells that has been selected to have the logic states written therein; and (c) determining, by the applied reading voltage, a synaptic weight through a sum of currents flowing through the one or more memory cells that has been selected to have the logic states written therein, wherein the selected one or more memory cells are recognized to operate as one synaptic element.