Methods and devices for forming nanostructure monolayers and devices including such monolayers
View Patent ↗Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, formation of arrays in spin-on-dielectrics, solvent annealing after nanostructure deposition, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices).
1. A method for forming a nanostructure array, the method comprising:
providing a first layer;
providing nanostructures dispersed in a solution comprising a liquid form of a spin-on-dielectric that comprises a photopolymerizable compound, and wherein the nanostructures comprise a silsesquioxane ligand coating;
disposing the solution on the first layer, whereby the nanostructures form a monolayer array on the first layer; and
curing the liquid form of the spin-on-dielectric to provide a solid form of the spin-on-dielectric.
2. The method of claim 1 , wherein the first layer comprises: (a) a dielectric material, (b) silicon oxide coated with hexamethyldisilizane, or (c) silicon nitride coated with hexamethyldisilizane.
3. The method of claim 1 , wherein the first layer is disposed on a semiconductor substrate.
4. The method of claim 3 , wherein the substrate comprises a source region, a drain region, and a channel region between the source and drain regions and underlying the monolayer array of nanostructures, and wherein the method further comprises disposing a gate electrode on the solid form of the spin-on-dielectric.
5. The method of claim 4 , the method comprising disposing a dielectric layer on the solid form of the spin-on-dielectric prior to disposing the gate electrode on the solid form of the spin-on-dielectric.
6. The method of claim 1 , wherein the solid form of the spin-on-dielectric comprises silicon oxide.
7. The method of claim 1 , wherein the liquid form of the spin-on-dielectric comprises a silsesquioxane that is mercapto-propyl-cyclohexyl polyhedral oligomeric silsesquioxane, hydrogen silsesquioxane, octavinyl dimethyl silyl silsesquioxane, octasilane silsesquioxane, or octavinyl-T8 silsesquioxane.
8. The method of claim 1 , further comprising:
exposing at least a first region of the first layer and the solution disposed thereon to light of an appropriate wavelength, thereby curing the spin-on-dielectric in the first region, while simultaneously protecting at least a second region of the first layer and the solution disposed thereon from the light, whereby the spin-on-dielectric in the second region remains uncured; and
removing the uncured spin-on-dielectric and the nanostructures therein from the first layer without removing the cured spin-on-dielectric and the nanostructures therein.
9. The method of claim 8 , wherein exposing at least a first region of the first layer and the solution disposed thereon to the light comprises exposing 10 or more, 50 or more, 100 or more, 1000 or more, 1×10 4 or more, 1×10 6 or more, 1×10 9 or more, or 1×10 12 or more discrete regions.
10. The method of claim 1 , wherein the monolayer array of nanostructures comprises a disordered array.
11. The method of claim 1 , wherein the monolayer array of nanostructures has a density greater than about 1×10 10 nanostructures/cm 2 , greater than about 1×10 11 nanostructures/cm 2 , greater than about 1×10 12 nanostructures/cm 2 , or greater than about 1×10 13 nanostructures/cm 2 .
12. The method of claim 1 , wherein variation in density of the nanostructures in the monolayer array is less than 10% across the monolayer.
13. The method of claim 1 , wherein the nanostructures comprise substantially spherical nanostructures or quantum dots.
14. The method of claim 1 , wherein the nanostructures have a work function of about 4.5 eV or higher.
15. The method of claim 1 , wherein the nanostructures comprise palladium, nickel, or ruthenium.
16. The method of claim 1 , wherein the nanostructures in the monolayer array are randomly distributed as a matrix in the solid form of the spin-on-dielectric.
17. The method of claim 1 , wherein the first layer comprises a material selected from the group consisting of: an oxide and a nitride.
18. The method of claim 1 , wherein the first layer comprises a material selected from the group consisting of: silicon oxide, silicon nitride, hafnium oxide, and alumina.
19. A method for forming a nanostructure array, the method comprising:
providing a first layer;
providing nanostructures dispersed in a solution comprising a liquid form of a spin-on-dielectric that comprises a photoresist, wherein each of the nanostructures comprises a silsesquioxane ligand associated with a surface of the nanostructure;
disposing the solution on the first layer, whereby the nanostructures form a monolayer array on the first layer; and
curing the liquid form of the spin-on-dielectric to provide a solid form of the spin-on-dielectric.
20. The method of claim 19 , wherein the first layer comprises a dielectric material.
21. The method of claim 20 , wherein the first layer comprises silicon oxide coated with hexamethyldisilizane, or wherein the first layer comprises silicon nitride coated with hexamethyldisilizane.
22. The method of claim 19 , wherein the first layer is disposed on a semiconductor substrate.
23. The method of claim 22 , wherein the first layer comprises a dielectric material and has a thickness of between about 1 nm and about 10 nm.
24. The method of claim 23 , wherein the substrate comprises a source region, a drain region, and a channel region between the source and drain regions and underlying the monolayer array of nanostructures, and wherein the method further comprises disposing a gate electrode on the solid form of the spin-on-dielectric.
25. The method of claim 24 , the method comprising disposing a dielectric layer on the solid form of the spin-on-dielectric prior to disposing the gate electrode on the solid form of the spin-on-dielectric.
26. The method of claim 19 , wherein disposing the solution on the first layer comprises spin coating the first layer with the solution.
27. The method of claim 19 , wherein the liquid form of the spin-on-dielectric comprises aluminum i-propoxide, tri-methyl aluminum, tri-ethyl aluminum, hafnium t-butoxide, hafnium ethoxide, tetrabenzyl hafnium, tris(cyclopentadienyl)lanthanum, tris(i-propylcyclopentadienyl)lanthanum, pentakis(dimethylamino)tantalum, tantalum methoxide, or tantalum ethoxide.
28. The method of claim 19 , wherein the liquid form of the spin-on-dielectric is a liquid form of a spin-on-glass, and wherein the solid form of the spin-on-dielectric is a solid form of a spin-on-glass.
29. The method of claim 19 , comprising:
exposing at least a first region of the first layer and the solution disposed thereon to light of an appropriate wavelength, thereby curing the spin-on-dielectric in the first region, while simultaneously protecting at least a second region of the first layer and the solution disposed thereon from the light, whereby the spin-on-dielectric in the second region remains uncured; and
removing the uncured spin-on-dielectric and the nanostructures therein from the first layer without removing the cured spin-on-dielectric and the nanostructures therein.
30. The method of claim 29 , wherein exposing at least a first region of the first layer and the solution disposed thereon to the light comprises exposing 10 or more, 50 or more, 100 or more, 1000 or more, 1×10 4 or more, 1×10 6 or more, 1×10 9 or more, or 1×10 12 or more discrete regions.
31. The method of claim 19 , wherein the monolayer array of nanostructures comprises a disordered array.
32. The method of claim 19 , wherein the monolayer array of nanostructures has a density greater than about 1×10 10 nanostructures/cm 2 , greater than about 1×10 11 nanostructures/cm 2 , greater than about 1×10 12 nanostructures/cm 2 , or greater than about 1×10 13 nanostructures/cm 2 .
33. The method of claim 19 , wherein variation in density of the nanostructures in the monolayer array is less than 10% across the monolayer.
34. The method of claim 19 , wherein the nanostructures comprise substantially spherical nanostructures or quantum dots.
35. The method of claim 19 , wherein the nanostructures have a work function of about 4.5 eV or higher.
36. The method of claim 19 , wherein the nanostructures comprise palladium, nickel, or ruthenium.
37. The method of claim 19 , wherein the nanostructures in the monolayer array are randomly distributed as a matrix in the solid form of the spin-on-dielectric.
38. The method of claim 19 , wherein the first layer comprises a material selected from the group consisting of: an oxide and a nitride.
39. The method of claim 19 , wherein the first layer comprises a material selected from the group consisting of: silicon oxide, silicon nitride, hafnium oxide, and alumina.