Silicon carbide nanoneedles and fabrication thereof
A product includes an elongated carbon-containing pillar having a bottom and a tip opposite the bottom. The width of the pillar measured 1 nm below the tip is less than 700 nm. A method includes masking a carbon-containing single crystal for defining masked regions and unmasked regions on the single crystal. The method also includes performing a plasma etch for removing portions of the unmasked regions of the single crystal, thereby defining a pillar in each unmasked region, and performing a chemical etch on the pillars at a temperature between 1200° C. and 1600° C. for selectively reducing a width of each pillar.
1. A product, comprising:
an elongated carbon-containing pillar having a bottom and a tip opposite the bottom,
wherein the width of the pillar measured 1 nm below the tip is less than 700 nm,
wherein the pillar, when formed, has no oxidation on an outer surface thereof.
2. The product as recited in claim 1 , wherein the tip is rounded.
3. The product as recited in claim 1 , wherein the pillar extends from a single crystal substrate having a bulk composition that is the same as the bulk composition of the pillar.
4. The product as recited in claim 3 , wherein the pillar has no higher concentration of defects per unit volume than the single crystal substrate.
5. The product as recited in claim 1 , wherein the pillar has a faceted peripheral outer surface.
6. The product as recited in claim 1 , wherein the pillar has a rounded peripheral outer surface.
7. The product as recited in claim 6 , wherein the peripheral outer surface of the pillar is rounded therealong from the bottom to the tip of the pillar.
8. The product as recited in claim 1 , wherein the pillar is SiC.
9. The product as recited in claim 1 , wherein the pillar is diamond.
10. The product as recited in claim 1 , comprising an array of the pillars extending from a substrate, the pillars and substrate having the same bulk composition throughout.
11. The product as recited in claim 10 , wherein at least some of the pillars have an inner channel extending along a longitudinal axis thereof.
12. The product as recited in claim 11 , wherein the substrate has channels therethrough in fluid communication with the channels of at least some of the pillars.
13. A method of making the product as recited in claim 1 , the method comprising:
masking a carbon-containing single crystal for defining masked regions and unmasked regions on the single crystal;
performing a plasma etch for removing portions of the unmasked regions of the single crystal, thereby defining a pillar in each unmasked region; and
performing a chemical etch on the pillars at a temperature between 1200° C. and 1600° C. for selectively reducing a width of each pillar.
14. The method as recited in claim 13 , wherein performing the chemical etch includes contacting the pillars with a gas having at least one etchant, the etchant being selected from the group consisting of: H, Cl, Br, and I.
15. The method as recited in claim 14 , comprising adding a defined amount of oxygen to the gas for reducing an extent of crystallographic etching.
16. The method as recited in claim 13 , wherein each pillar comprises a bottom and a tip opposite the bottom, wherein the width of the pillar measured 1 nm below the tip is less than 700 nm.
17. The method as recited in claim 13 , wherein each pillar has an inner channel extending along a longitudinal axis thereof.
18. A product, comprising:
an elongated carbon-containing pillar having a bottom and a tip opposite the bottom,
wherein the width of the pillar measured 1 nm below the tip is less than 700 nm,
wherein the pillar has an inner channel extending along a longitudinal axis thereof.
19. The product as recited in claim 18 , wherein the pillar extends from a single crystal substrate having a bulk composition that is the same as the bulk composition of the pillar, wherein the substrate has a channel therethrough in fluid communication with the channel of the pillar.