Conductive filament based memory elements and methods with improved data retention and/or endurance
View Patent ↗A memory element can include a memory layer formed between two electrodes; at least one element within the memory layer that is oxidizable in the presence of an electric field applied across the electrodes; and an inhibitor material incorporated into at least a portion of the memory layer that decreases an oxidation rate of the at least one element within the memory layer with respect to the memory layer alone. Methods of forming such a memory element are also disclosed.
1. A memory element, comprising:
a memory material formed between two electrodes;
at least one element within the memory material that is oxidizable in the presence of an electric field applied across the electrodes; and
an inhibitor material incorporated into at least a portion of the memory material that decreases an oxidation rate of the at least one element within the memory material with respect to the memory material alone.
2. The memory element of claim 1 , wherein:
the memory material has a first surface opposing a first electrode and a second surface opposing a second electrode; and
the inhibitor material extends into only a portion of the memory material from the first surface.
3. The memory element of claim 1 , wherein:
the inhibitor material is selected from the group of:
a hole scavenger that occupies a hole or increases a formation energy of a hole within the memory material;
an electron scavenger that binds with free electrons within the memory material;
a reducing agent that provides electrons for reducing ionic forms of the at least one element;
a scavenger of predetermined oxidizer precursors that binds with such oxidizer precursors, an oxidizer precursor being a compound that forms an oxidizing agent of the at least one element;
a scavenger of oxidizers that prevent such oxidizers from oxidizing the at least one element; and
a scavenger of any compound selected from the group of: halides, nitrides, nitrates, or sulfur oxides.
4. The memory element of claim 3 , wherein:
the scavenger of oxidizer precursors scavenges precursors selected from the group of: water and oxygen.
5. The memory element of claim 1 , wherein:
the memory material includes sulfur; and
the inhibitor material is a scavenger of any selected from the group of: sulfur with an oxidation state of -2 (S 2− ), HS—, or H 2 S.
6. The memory element of claim 1 , wherein:
the inhibitor material is a scavenger of a compound, or precursor of a compound, that forms an oxide of the at least one element.
7. The memory element of claim 1 , wherein
the inhibitor material is selected from the group of: tin chloride (SnCl 2 ), thirourea (SC(NH 2 ) 2 ), cyanine, a heterocyclic compound including a suitable mercapto tetrazole, a nitrite comprising NO 2 31 with a selected cation, a nitrite, a sulfite, a hydroquinone, a carbohydrazide, a nitrite, a sulfite, a hydroquinone, and a carbohydrazide.
8. The memory element of claim 1 , wherein:
the inhibitor material is a metal different from the at least one element.
9. The memory element of claim 8 , wherein:
the inhibitor material is selected from: Cu, Au, Pt, Pd, Ir, Rh, and Os.
10. The memory element of claim 1 , wherein:
one of the electrodes comprises the at least one element.
11. The memory element of claim 1 , wherein:
the oxidation inhibitor material forms a monolayer within the memory material.
12. The memory element of claim 1 , wherein:
the oxidation inhibitor material is non-contiguous within the memory material.
13. The memory element of claim 1 , wherein:
the at least one element is selected from: silver and copper.