Method of forming a nanostructure
View Patent ↗A method of forming a discrete nanostructured element at one or more predetermined locations on a substrate is presented. The method includes forming a mask member over the substrate. A window is formed in the mask member at each of one or more locations at which it is required to form the nanostructured element thereby to expose a portion of a surface of the substrate. A portion of the substrate exposed by the window at the one or more locations is removed to form one or more recesses in the substrate. The method further includes forming a layer of a nanostructure medium over a surface of the recess and annealing the structure thereby to form the nanostructured element in each of the one or more recesses. The nanostructured element includes a portion of the nanostructure medium and has an external dimension along at least two substantially orthogonal directions of less than substantially 100 nm.
1. A method of forming a discrete nanostructured element at one or more predetermined locations on a substrate comprising:
forming a mask member over said substrate;
forming a window in said mask member to expose a portion of a surface of said substrate at each of the one or more locations where said nanostructured element is to be formed;
removing a portion of said substrate exposed by said window at said one or more locations to form one or more recesses in said substrate;
forming a layer of a nanostructure medium over a surface of said recess and the mask member; and
annealing the layer of the nanostructure medium to form said nanostructured element in each of said one or more recesses, said nanostructured element comprising a portion of said nanostructure medium, said nanostructured element having an external dimension along at least two substantially orthogonal directions less than or substantially equal to 100 nm; and
removing the mask member after annealing the layer of the nanostructure medium.
2. A method as claimed in claim 1 wherein the step of forming said one or more recesses comprises the step of etching said structure.
3. A method as claimed in claim 1 wherein the step of forming a recess in said substrate comprises forming a recess having one or more walls defining a base shape corresponding to at least one selected from amongst a portion of a pyramidal structure, a portion of a square-base pyramidal structure, a portion of a cube, a portion of a cuboid, a concave rounded surface, a portion of a surface of a sphere, a portion of a surface of a cylinder and a groove of substantially v-shaped or u-shaped cross-section.
4. A method as claimed in claim 3 wherein at least one of said walls of said base shape is generally defined by a crystal plane of said substrate.
5. A method as claimed in claim 3 wherein said recess comprises a passageway having said base shape provided at a first end of said passageway, a second end of the passageway opposite said first end having an opening at said surface of said substrate.
6. A method as claimed in claim 5 wherein said passageway has bends, kinks, jogs and/or other locations at which a longitudinal axis of said passageway changes its orientation relative to other portions of the passageway.
7. A method as claimed in claim 1 wherein the nanostructured element comprises a nanoparticle.
8. A method as claimed in claim 1 wherein said recess comprises an elongate groove.
9. A method as claimed in claim 8 wherein said groove has a portion having a substantially v-shaped or u-shaped cross-section, said nanostructured elements being provided along an apex of said v-shaped or u-shaped portion of said groove.
10. A method as claimed in claim 8 wherein the nanostructured element comprises a nanowire.
11. A method as claimed in claim 1 wherein said mask member comprises silicon oxide.
12. A method as claimed in claim 1 wherein said nanostructure medium comprises a catalyst material.
13. A method as claimed in claim 1 wherein the nanostructured element is formed at an intersection of non-parallel walls of the recesses.
14. A method as claimed in claim 1 wherein said nanostructure medium comprises at least one selected from amongst Au, Ni, Al, Co and Ti.
15. A method as claimed in claim 1 further comprising the step of heating said nanostructure thereby to form a further nanostructure.
16. A method as claimed in claim 15 wherein the step of heating said nanostructure comprises the step of heating said nanostructure in the presence of a vapor.
17. A method as claimed in claim 16 wherein said vapour comprises a vapor bearing at least one selected from amongst a Group II element, a Group III element, a Group IV element, a Group V element and a Group VI element of the periodic table.
18. A method as claimed in claim 17 wherein said vapor comprises at least one selected from amongst a carbon-bearing vapor, a nitrogen-bearing vapor and a boron-bearing vapor.
19. A method as claimed in claim 1 wherein the step of forming the nanostructure medium comprises the step of forming a generally continuous layer of said medium.
20. A method as claimed in claim 1 wherein the step of forming the layer of the nanostructure medium comprises lining the surface of the mask member and walls of the recesses without filling the recesses.
21. A method of forming a device comprising:
providing a substrate prepared with a recess, wherein the substrate comprises a mask member over a top surface of the substrate, and the mask member comprises a window which exposes the recess, wherein the window is formed by mask and etch processes;
lining a top surface of the mask member and walls of the recess with a layer of a nanostructure medium without filling the recess;
annealing the layer of the nanostructure medium to form a nanostructure in the recess wherein the nanostructure comprising a portion of the nanostructure medium; and
removing the mask member after annealing the layer of the nanostructure medium.
22. The method of claim 21 wherein the nanostructure is formed at an intersection of non-parallel walls of the recesses.
23. A method of forming a nanowire at one or more predetermined locations on a substrate comprising the steps of:
forming a mask member over said substrate;
forming an elongate window in said mask member to expose a portion of a surface of said substrate at each of the one or more locations where said nanowire is to be formed;
etching a portion of said substrate exposed by said window at said one or more locations to form one or more grooves in said substrate;
forming a layer of a wire medium over a surface of said groove; and
annealing the layer of the wire medium thereby to form said nanowire in each of said one or more grooves along a bottom area of each of the grooves, said nanowire comprising a portion of said wire medium.
24. A method as claimed in claim 23 wherein said groove comprises a portion having a substantially v-shaped or u-shaped cross-section, said nanowire being formed along an apex of said portion of said groove.