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US 12,672,489 B1Granted
Resistive switching memory having confined filament formation and methods thereof
AssigneeCrossbar, Inc.
InventorsSundar Narayanan, Wee Chen Gan, Natividad Vasquez, Jr., Wei Ti Lee
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Abstract
Resistive switching memory cells having filament-based switching mechanisms are provided. By way of example, resistive switching memory cells having resistive filaments constrained to a core of the cell are disclosed. In other examples, methods for fabricating resistive switching memory cells to constrain a conductive filament formed in the resistive switching memory cell to a central portion of core of the cell are disclosed.
Claims21
A resistive switching memory cell, comprising:
- a bottom electrode formed within a dielectric material overlying a substrate;
- a conductive layer overlying and in contact with both the bottom electrode and the dielectric layer;
- a first resistive switching layer formed of an electrically resistive material overlying the conductive layer;
- a second resistive switching layer formed overlying the first resistive switching layer, wherein the first resistive switching layer further comprises a gap formed therein that exposes a surface of the conductive layer directly to a portion of the second resistive switching layer within the gap in the first resistive switching layer;
- and
- a top electrode overlying the second resistive switching layer and comprising conductive particles that diffuse within the second resistive switching layer in response to a suitable electrical stimulus applied to the resistive switching memory cell.
3 more elements
A resistive switching memory cell, comprising:
- a bottom electrode;
- a conductive layer overlying the bottom electrode;
- a switching layer overlying and in physical contact with the conductive layer, wherein the switching layer comprises an electrically resistive material at least in part permeable to conductive particles;
- a top electrode layer overlying and in physical contact with the switching layer, wherein the top electrode layer comprises a material of conductive particles capable of being ionized, wherein the conductive particles drift into the switching layer in response to a suitable electrical stimulus applied to the resistive switching memory cell;
- and
- a capping layer overlying the top electrode layer;
- wherein the switching layer and the top electrode layer further comprise:
- a central core comprising the material of conductive particles overlying the electrically resistive material;
- a perimeter shell about the central core formed of an oxidized, etch-fractured material of conductive particles overlying an oxidized, etch-fractured electrically resistive material.
6 more elements
A method of fabricating a resistive switching device, comprising:
- forming a conductive layer over a bottom electrode situated within a dielectric layer overlying a semiconductor substrate;
- forming a switching layer overlying and in physical contact with the conductive layer, wherein the switching layer comprises an electrically resistive material at least in part permeable to conductive particles;
- forming a top electrode layer overlying and in physical contact with the switching layer, wherein the top electrode layer provides the conductive particles that drift into the switching layer in response to an electrical stimulus applied across the bottom electrode and the top electrode;
- forming a capping layer overlying the top electrode layer;
- etching the capping layer, the top electrode layer and the switching layer to form a discrete resistive switching device comprising an etched capping layer, an etched top electrode layer and an etched switching layer;
- selectively etching a perimeter of the discrete resistive switching device and removing an exterior portion of the etched top electrode layer to an interior depth;
- and
- depositing a high electrical resistive conformal oxide material about the resistive switching device and filling the interior depth of the etched top electrode, wherein the oxide material has an electrical resistance higher than the electrically resistive material of the switching layer, or has lower permeability to the conductive particles than the electrically resistive material of the switching layer.
5 more elements
Dependencies are inferred from the claim text.