Memory cells and methods of fabrication
Memory cells are disclosed, which cells include a cell material and an ion-source material over the cell material. A discontinuous interfacial material is included between the cell material and the ion-source material. Also disclosed are fabrication methods and semiconductor devices including the disclosed memory cells.
1. A method of forming a memory cell, the method comprising:
forming an interfacial material of an adhesion-promoter compound comprising adherent atoms and at least one ligand bonded to the adherent atoms on a cell material;
removing the at least one ligand to form a discontinuous interfacial material consisting of the adherent atoms on the cell material, each adherent atom separated from an adjacent adherent atom by a distance greater than or equal to a width of the at least one ligand; and
forming a metal ion-source material comprising a copper-containing material or a silver-containing material over the discontinuous interfacial material consisting of the adherent atoms, the discontinuous interfacial material adhering the cell material to the metal ion-source material by the adherent atoms.
2. The method of claim 1 , wherein removing the at least one ligand comprises exposing the adhesion-promoter compound to a reagent.
3. The method of claim 2 , wherein exposing the adhesion-promoter compound to a reagent comprises reacting the reagent with the at least one ligand to disassociate the at least one ligand from the adherent atoms.
4. The method of claim 2 , wherein exposing the adhesion-promoter compound to a reagent comprises exposing the adhesion-promoter compound to ammonia.
5. The method of claim 1 , wherein removing the at least one ligand comprises forming the discontinuous interfacial material having a thickness of one adherent atom.
6. The method of claim 1 , wherein forming an interfacial material of an adhesion-promoter compound comprising adherent atoms and at least one ligand bonded to the adherent atoms comprises forming an interfacial material of an adhesion-promoter compound comprising metal atoms bonded to at least one halide atom.
7. The method of claim 1 , wherein forming an interfacial material of an adhesion-promoter compound comprises forming the interfacial material using atomic layer deposition.
8. The method of claim 1 , wherein forming an interfacial material of an adhesion-promoter compound comprising adherent atoms and at least one ligand bonded to the adherent atoms on a cell material comprises forming the interfacial material on the cell material comprising a transition metal oxide, a silicate, an oxynitride, a high-k dielectric material, or combinations thereof.
9. A method of forming a memory cell, the method comprising:
forming a partial monolayer comprising an adhesion-promoter compound on a surface of a cell material subjected to a vacuum condition, the partial monolayer occupying less than all reaction surface sites of the cell material;
forming a saturated film of metal ion-source atoms on the partial monolayer comprising the adhesion-promoter compound; and
releasing the vacuum condition.
10. The method of claim 9 , wherein forming a partial monolayer comprises reacting a gas comprising the adhesion-promoter compound with the reaction surface sites to occupy less than about 60% of all the reaction surface sites of the cell material.
11. The method of claim 9 , wherein forming a partial monolayer and forming a saturated film of metal ion-source atoms comprises forming the partial monolayer and forming the saturated film of metal ion-source atoms by atomic layer deposition without releasing the vacuum condition.
12. The method of claim 9 , wherein forming a partial monolayer and forming a saturated film of metal ion-source atoms comprises moving a substrate comprising the cell material between multiple chambers of a tool without releasing the vacuum condition.
13. The method of claim 9 , wherein forming a saturated film of metal ion-source atoms comprises reacting a gas comprising the metal ion-source atoms with reactive sites of the partial monolayer.
14. The method of claim 13 , wherein forming a saturated film of metal ion-source atoms comprises bonding a metal ion-source atom with each reactive site of the partial monolayer.
15. A memory cell comprising:
a cell material;
a partial monolayer of adherent atoms, the adherent atoms occupying less than all reaction sites of the cell material; and
a saturated film of metal ion-source atoms over the partial monolayer of adherent atoms, the adherent atoms spaced apart a distance sufficient to enable the metal ion-source atoms to drift through the partial monolayer.
16. The memory cell of claim 15 , wherein the partial monolayer of adherent atoms comprises evenly spaced adherent atoms.
17. The memory cell of claim 15 , wherein the cell material comprises a dielectric material.
18. The memory cell of claim 15 , wherein the cell material is permeable to the metal ion-source atoms.
19. A method of forming a memory cell, the method comprising:
forming an adhesion-promoter compound on a cell material, the adhesion-promoter compound comprising adherent atoms bonded to the cell material and at least one ligand bonded to the adherent atoms;
removing the at least one ligand from the adhesion-promoter compound so that only the adherent atoms are bonded to the cell material, each adherent atom separated from an adjacent adherent atom by a distance greater than or equal to a width of the at least one ligand; and
forming a metal ion-source material comprising ion-source atoms over the adherent atoms to form a discontinuous interfacial material.
20. The method of claim 19 , wherein forming a metal ion-source material comprising ion-source atoms over the adherent atoms comprises bonding the adherent atoms and the ion-source atoms.
21. The method of claim 19 , wherein forming a metal ion-source material comprising ion-source atoms over the adherent atoms comprises forming the metal ion-source material comprising metal ions.
22. The method of claim 19 , wherein forming a metal ion-source material comprising ion-source atoms over the adherent atoms to form a discontinuous interfacial material comprises forming interfacial complexes comprising the adherent atoms and the ion-source atoms, the interfacial complexes spaced apart from one another.
23. The method of claim 19 , wherein forming a metal ion-source material comprising ion-source atoms over the adherent atoms to form a discontinuous interfacial material comprises forming the discontinuous interfacial material consisting of a reaction product of the adherent atoms and the ion-source atoms.