Apparatus and Methods for Electrical Switching
AssigneeMassachusetts Institute of Technology
InventorsJeehwan Kim, Shinhyun Choi
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Abstract
Electrical switching technologies employ the otherwise undesirable line defect in crystalline materials to form conductive filaments. A switching cell includes a crystalline layer disposed between an active electrode and another electrode. The crystalline layer has at least one channel, such as a line defect, extending from one surface of the crystalline layer to the other surface. Upon application of a voltage on the two electrodes, the active electrode provides metal ions that can migrate from the active electrode to the other electrode along the line defect, thereby forming a conductive filament. The switching cell can precisely locate the conductive filament within the line defect and increase the device-to-device switching uniformity.
Claims30
An apparatus for electrical switching, the apparatus comprising:
- a crystalline layer having a first side and a second side opposite the first side, the crystalline layer having at least one channel extending from the first side to the second side;
- a first electrode disposed on the first side of the crystalline layer, the first electrode having a first solid solubility less than 1% in the crystalline layer;
- and
- a second electrode disposed on the second side of the crystalline layer, the second electrode having a second solid solubility less than 1% in the crystalline layer,
- wherein the first electrode comprises an active material to provide at least one metal ion migrating along the at least one channel in response to a first voltage applied across the first electrode and the second electrode.
A method of actuating a device comprising a crystalline layer having at least one channel extending from a first side of the crystalline layer to a second side of the crystalline layer, a first electrode comprising an active material disposed on the first side of the crystalline layer, and a second electrode disposed on the second side of the crystalline layer, the method comprising:
- applying a first voltage, having a first sign, across the first electrode and the second electrode, the first voltage causing a plurality of metal ions of the active material to form a conductive filament extending between the first electrode and the second electrode along the at least one channel.
An electrical switching device comprising:
- a switching medium comprising crystalline SiGe and having a first side and a second side, the switching medium having a thickness of about 10 nm to about 100 nm and at least one line defect extending from the first side to the second side, the at least one line defect having a width of about 0.1 nm to about 30 nm;
- a first electrode comprising an active material and disposed on the first side of the switching medium, the first electrode having a first solid solubility less than 1% in the switching medium;
- and
- a second electrode disposed on the second side of the crystalline layer, the second electrode having a second solid solubility less than 1% in the crystalline layer
- wherein a plurality of metal ions from the first electrode is configured to migrate along the at least one line defect to form a conductive filament in the at least one line defect in response to a first voltage applied between the first electrode and the second electrode, and
- wherein the plurality of metal ions is configured to retreat back to the first electrode in response to a second voltage applied between the first electrode and the second electrode, the second voltage having a second polarity opposite to a first polarity of the first voltage.
A method of fabricating an electrical switching device, the method comprising:
- forming a crystalline layer on a conductive substrate, the crystalline layer having a first side on the conductive substrate and a second side opposite the first side, the crystalline layer having at least one channel extending from the first side to the second side;
- forming an electrode, comprising an active material, on the second side of the crystalline layer, the electrode having a first solid solubility less than 1% in the crystalline layer.
Dependencies are inferred from the claim text.