Graphene layer formation at low substrate temperature on a metal and carbon based substrate
A system and method for forming graphene layers on a substrate. The system and methods include direct growth of graphene on diamond and low temperature growth of graphene using a solid carbon source.
1. A method of forming single domain graphene on a substrate, comprising the steps of,
providing a diamond substrate;
forming a transition metal layer on the diamond substrate;
forming at least one hole in the transition metal layer and diamond substrate;
dissolving the transition metal layer into the diamond substrate by an annealing step; and
cooling the substrate;
forming single domain graphene suspended over the at least one hole.
2. The method of claim 1 , wherein the at least one hole is a plurality of holes of diameter varying from 300 nm up to 1 μm.
3. The method as defined in claim 1 wherein the transition metal layer comprises Ni.
4. The method as defined in claim 1 wherein the annealing step includes placing the diamond substrate in a rapid thermal vacuum furnace with a H 2 /Ar gas mixture and wherein an annealing temperature is about 800-1000° C. and the cooling step is performed at a rate of about 600 C./minute.
5. The method as defined in claim 1 wherein a thickness of the transition metal layer is established such that upon completing the dissolving step the transition metal from the transition metal layer has no trace amount in sub-surface regions of the carbon precursor.
6. A method of forming graphene on a substrate, comprising the steps of,
providing a diamond substrate;
forming a transition metal layer on the diamond substrate;
dissolving the transition metal layer into the diamond substrate by an annealing step having an annealing temperature is about 800-1000° C.; and
cooling the substrate, thereby forming a graphene layer from the diamond substrate as a carbon precursor, the cooling performed at a rate of about 600 C./minute; wherein a thickness of the transition metal layer is established such that upon completing the dissolving step the transition metal from the transition metal layer has no trace amount in sub-surface regions of the carbon precursor.
7. The method as defined in claim 6 wherein the diamond substrate is selected from the group of (a) single crystal diamond and (b) at least one of: UNCD/NCD/MCD (microcrystalline diamond) thin film diamond deposited on a Si substrate.
8. The method as defined in claim 6 wherein the transition metal layer comprises Ni.
9. The method as defined in claim 6 wherein the annealing step includes placing the diamond substrate in a vacuum furnace with a H 2 /Ar gas mixture.
10. The method of claim 6 , wherein the substrate is heated to the annealing temperature in about 30 s for annealing.