Gas-phase functionalization of surfaces including carbon-based surfaces
View Patent ↗The invention provides methods functionalizing a planar surface of a graphene layer, a graphite surface, or microelectronic structure. The graphene layer, graphite surface, or planar microelectronic structure surface is exposed to at least one vapor including at least one functionalization species that non-covalently bonds to the graphene layer, a graphite surface, or planar microelectronic surface while providing a functionalization layer of chemically functional groups, to produce a functionalized graphene layer, graphite surface, or planar microelectronic surface.
1. A method for functionalizing a graphene layer comprising:
exposing the graphene layer to at least one vapor including at least one functionalization species, selected from the group consisting of NO 2 and CH 3 ONO, that non-covalently bonds to the graphene layer while providing a functionalization layer of chemically functional groups, to produce a functionalized graphene layer; and
exposing the graphene layer to at least one vapor stabilization species to form a stabilization layer that stabilizes the functionalization layer against desorption from the graphene layer while providing chemically functional groups at the graphene layer, to produce a stabilized graphene layer.
2. The method of claim 1 wherein the graphene layer is disposed on a substrate.
3. The method of claim 1 wherein the graphene layer is disposed on a layer of oxide.
4. The method of claim 1 wherein the chemically functional groups comprise —CH 3 groups.
5. The method of claim 1 wherein the at least one vapor comprises a first vapor including a first functionalization species that is physisorbed on the graphene layer and a second vapor including a second functionalization species that reacts with the physisorbed first functionalization species to form on the graphene layer a functionalization layer of chemically functional groups.
6. The method of claim 5 wherein the second functionalization species is selected from a group consisting of trimethylaluminum, dimethylzinc, trimethylgallium, trimethylindium, trimethylbismuth, tetrakis(dimethylamido)hafnium, and tetrakis(dimethylamido)zirconium.
7. The method of claim 5 wherein the graphene layer exposure comprises cyclically alternating exposure of the graphene layer to the first vapor and the second vapor.
8. The method of claim 1 wherein the functionalization species exposure of the graphene layer and the stabilization species exposure of the graphene layer are carried out at a temperature of about 25° C.
9. The method of claim 1 further comprising exposing the stabilized graphene layer to at least one material layer precursor species that deposits a material layer on the stabilized the graphene layer.
10. The method of claim 7 wherein the cyclically alternating exposure comprises cycles of atomic layer deposition with the first functionalization species and the second functionalization species.
11. The method of claim 7 wherein the cyclically alternating exposure is carried out a number of exposure cycles that forms a functionalization layer of no greater than one monolayer in thickness.
12. The method of claim 7 wherein the cyclically alternating exposure is carried out a number of exposure cycles that forms a functionalization layer of no greater than about one nanometer in thickness.
13. The method of claim 1 wherein the stabilization species reacts with the functionalization layer to covalently bond to the functionalization layer.
14. The method of claim 1 wherein the at least one vapor stabilization species consists of water and a species selected from a group consisting of trimethylaluminum, dimethylzinc, trimethylgallium, trimethylindium, trimethylbismuth, tetrakis(dimethylamido)hafnium, and tetrakis(dimethylamido)zirconium.
15. The method of claim 1 wherein the stabilization layer that is formed comprises Al 2 O 3 .
16. The method of claim 1 wherein the vapor stabilization species exposure of the functionalized graphene layer comprises cyclically alternating exposure of the functionalized graphene layer to a first stabilization precursor and a second stabilization precursor.
17. The method of claim 16 wherein the cyclically alternating exposure comprises cycles of atomic layer deposition with the first stabilization precursor and the second stabilization precursor.
18. A method for functionalizing a graphene layer comprising:
exposing the graphene layer to at least one vapor including at least one functionalization species that non-covalently bonds to the graphene layer while providing a functionalization layer of chemically functional groups, to produce a functionalized graphene layer;
exposing the functionalized graphene layer to at least one vapor stabilization species to form a stabilization layer that stabilizes the functionalization layer against desorption from the graphene layer while providing chemically functional groups at the graphene layer, to produce a stabilized graphene layer; and
forming an electrically insulating layer over the stabilization layer.
19. The method of claim 18 wherein the electrically insulating layer that is formed over the stabilization layer is selected from a group consisting of Al 2 O 3 , LaAlO 3 , HfO 2 , ZrO 2 , Ta 2 O 5 , and mixtures thereof.
20. The method of claim 18 further comprising forming an electrically conducting layer over the insulating layer.
21. The method of claim 20 wherein the electrically conducting layer is selected from a group consisting of Rh, Pd, WN, and TiN.
22. The method of claim 18 wherein the graphene layer is disposed on a substrate.
23. The method of claim 18 wherein the graphene layer is disposed on a layer of oxide.
24. The method of claim 18 wherein the stabilization layer that is formed comprises Al 2 O 3 .
25. The method of claim 18 wherein the chemically functional groups comprise —CH 3 groups.