Methods, systems, and devices for parallel drift cancellation are described. In some instances, during a first duration, a first voltage may be applied to a word line to threshold one or more memory cells included in a first subset of memory cells. During a second duration, a second voltage may be applied to the word line to write a first logic state to one or more memory cells included in the first subset and to threshold one or more memory cells included in a second subset of memory cells. During a third duration, a third voltage may be applied to the word line to write a second logic state to one or more memory cells included in the second subset of memory cells.

This application relates to computing circuitry (200), in particular for analogue computing circuitry suitable for neuromorphic computing. The circuitry (200) has a plurality of memory cells (201), each memory cell having an input electrode (201) for receiving a cell input signal and an output (203.sub.P, 203.sub.N) for outputting a cell output signal (I.sub.P, I.sub.N), with first and second paths connecting the input electrode to the output. The cell output signal thus depends on a differential current between the first and second paths due to the cell input signal. Each memory cell also comprises at least one programmable-resistance memory element (204) in each of the first and second paths and is controllable, by selective programming of the programmable-resistance memory elements, to store a data digit that can take any of at least three different values. The plurality of memory cells are configured into one or more sets (205) of memory cells and a combiner module (206) receives the cell output signals from each of the memory cells in at least one set, and combines the cell output signals with a different scaling factor applied to each of the cell output signals.

An embodiment non-volatile memory device includes an array of memory cells in rows and columns; a plurality of local bitlines, the memory cells of each column being coupled to a corresponding local bitline; a plurality of main bitlines, each main bitline being coupleable to a corresponding subset of local bitlines; a plurality of program driver circuits, each having a corresponding output node and injecting a programming current in the corresponding output node, each output node coupleable to a corresponding subset of main bitlines. Each program driver circuit further includes a corresponding limiter circuit that is electrically coupled, for each main bitline of the corresponding subset, to a corresponding sense node whose voltage depends, during writing, on the voltage on the corresponding main bitline. Each limiter circuit turns off the corresponding programming current, in case the voltage on any of the corresponding sense nodes overcomes a reference voltage.

A memory circuit includes a first driver circuit, a first column of memory cells coupled to the first driver circuit, a first current source, a tracking circuit configured to track a leakage current of the first column of memory cells, and a footer circuit coupled to the first column of memory cells, the first current source and the tracking circuit.

A process is provided to trim PCRAM cells to have consistent programming curves. Initial programming curves of PCRAM cells are measured. A target programming curve is set up for the PCRAM cells. Each PCRAM cell is then modulated individually to meet the target programming curve.

An apparatus for reading a bit of a memory array includes a bit cell column, voltage enhancement circuitry, and control circuitry. The voltage enhancement circuitry is configured to couple a bitline to a reference node. The control circuitry is configured to, in response to a read request for a bitcell element of a plurality of bitcell elements, couple a current source to the bitcell column such that a read current from the current source flows from the source line, through the bitcell column and the voltage enhancement circuitry, to the reference node and determine a state for the bitcell element based on a voltage between the source line and the reference node. The voltage enhancement circuitry is configured to generate, when the read current flows through the voltage enhancement circuitry, a voltage at the bitline that is greater than a voltage at the reference node.

In one embodiment, a state is encoded into a memory cell comprising a phase change material (PM) region and a select device (SD) region by: applying a first current in the memory cell over a first time period, wherein the first current applied over the first time period causes the PM region of the memory cell to be placed into an amorphous state and the SD region of the memory cell to be placed into an amorphous state; and applying a second current in the memory cell over a second time period after the first time period, wherein the second current applied over the third time period causes the SD region of the memory cell to be placed into a crystalline state and the PM region of the memory cell to remain in the amorphous state.

In a method for using or forming a semiconductor structure. The semiconductor structure may include a resistive random access memory (RRAM) gate with a first electrode and a second electrode. The RRAM gate may also include a switching layer that includes a dielectric material having a switching layer k-value and a switching layer thermal conductivity. The RRAM gate may also include a complimentary switching (CS) mitigation layer with a material having a CS k-value that is lower than the switching layer k-value and a CS thermal conductivity that is higher than the switching layer thermal conductivity.

A non-volatile memory includes a first semiconductor layer vertically stacked on a second semiconductor layer and including a first memory group, a second memory group, a third memory group and a fourth memory group. The second semiconductor layer includes a first region, a second region, a third region and a fourth region respectively underlying the first memory group, second memory group, third memory group and fourth memory group. The first region includes one driving circuit connected to memory cells of one of the second memory group, third memory group and fourth memory group through a first word line, and another driving circuit connected to memory cells of the first memory group through a first bit line, wherein the first word line and first bit line extend in the same horizontal direction.

A projected memory device includes a carbon-based projection component. The device includes two electrodes, a memory segment, and a projection component. The projection component and the memory segment form a dual element that connects the two electrodes. The projection component extends parallel to and in contact with the memory segment. The memory segment includes a resistive memory material, while the projection component includes a thin film of non-insulating material that essentially comprises carbon. In a particular implementation, the non-insulating material and the projection component essentially comprises amorphous carbon. Using carbon and, in particular, amorphous carbon, as a main component of the projection component, allows unprecedented flexibility to be achieved when tuning the electrical resistance of the projection component.