International Business Machines Corporation

Benedikt J Kersting

Abu Sebastian

Ghazi Sarwat Syed

Manuel Le Gallo-Bourdeau

Vara Sudananda Prasad Jonnalagadda

Wabe W Koelmans

Vara S P Jonnalagadda

Martin Salinga

Timothy Mathew Philip

Timoleon Moraitis

Athanasios Vasilopoulos

Julian Röttger Büchel

The invention is notably directed to a method of programming memory elements of an in-memory computing (IMC) device. The IMC applies a SET signal to the K memory elements of said each cell to set each of the K memory elements to a SET state and reading K conductance values of the K memory elements in the SET state. The IMC adjusts, based on the K conductance values read and the target conductance value, a conductance value of at least one of the K memory elements to match a summed conductance of the K memory elements of said each cell with the target conductance value. The IMC maximizes a number of the K memory elements that are either in their SET state or in a RESET state of zero conductance nominal value, such that at most one of the K memory elements is neither in a SET state nor in a RESET state.

Accurate programming of analog memory devices of in-memory processing devices having a crossbar array structure

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.

Projected memory device with carbon-based projection component

A memory device enabling a reduced minimal conductance state may be provided. The device comprises a first electrode, a second electrode and phase-change material between the first electrode and the second electrode, wherein the phase-change material enables a plurality of conductivity states depending on the ratio between a crystalline and an amorphous phase of the phase-change material. The memory device comprises additionally a projection layer portion in a region between the first electrode and the second electrode. Thereby, an area directly covered by the phase-change material in the amorphous phase in a reset state of the memory device is larger than an area of the projection layer portion oriented to the phase-change material, such that a discontinuity in the conductance states of the memory device is created and a reduced minimal conductance state of the memory device in a reset state is enabled.

Projected memory device with reduced minimum conductance state

A neuromorphic memory element comprises a memristor, a plurality of the neuromorphic memory elements and a method for operating the same may be provided. The memristor comprises an input signal terminal, an output signal terminal, and a control signal terminal, and a memristive active channel comprising a phase change material. The memristive active channel extends longitudinal between the input signal terminal and the output signal terminal, and a control signal voltage at the control signal terminal is configured to represent volatile biological neural processes of the neuromorphic memory element, and a bias voltage between the input signal terminal and the output signal terminal is configured to represent non-volatile biological neural processes of the neuromorphic memory element.

Multi-terminal neuromorphic device

A memristor memory device comprises a memristive memory cell, an input terminal, an output terminal, and a gate terminal. The input terminal and the output terminal are directly attached to the memristive memory cell, and the gate terminal is electrically isolated from the memristive memory cell. The gate terminal is configured for receiving an electrical signal for a volatile modulation of a conductance of the memristive memory cell, by which a correction of non-ideal conductance modulations of the memristor memory device is achieved.

Drift and noise corrected memristive device

The invention is directed to a resistive memory device comprising a control unit for controlling a memory cell of the memory device. The memory cell includes a first terminal, a second terminal and a phase change segment comprising a phase-change material. The phase change segment is arranged between the first terminal and the second terminal. The phase change material is antimony. The phase change segment retains an amorphous region during a write operation. The control unit, during the write operation, applies an electrical programming pulse to the terminals to cause a portion of the phase change segment to transition from a crystalline phase to an amorphous phase comprising the amorphous region. A trailing edge duration of the electrical programming pulse is adjusted based on ambient temperature to prevent re-crystallization of the amorphous region. Shorter trailing edge durations are used at increasing ambient temperatures.

Resistive memory device

The invention is notably directed to a resistive memory device comprising a control unit for controlling the resistive memory device and a plurality of memory cells. The plurality of memory cells includes a first terminal, a second terminal and a phase change segment comprising a phase-change material for storing information in a plurality of resistance states. The phase change segment is arranged between the first terminal and the second terminal. The phase change material consists of antimony. Furthermore, at least one of the dimensions of the phase change segment is smaller than 15 nanometers. Additional implementations of the resistive memory device include a related method, a related control unit, a related memory cell and a related computer program product.

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Rueschlikon, Switzerland

Benedikt J Kersting