Graphene formation utilizing solid phase carbon sources
A method for forming a single, few-layer, or multi-layer graphene and structure is described incorporating selecting a substrate having a buried layer of carbon underneath a metal layer, providing an ambient and providing a heat treatment to pass carbon through the metal layer to form a graphene layer on the metal layer surface or incorporating a metal-carbon layer which is heated to segregate carbon in the form of graphene to the surface or chemically reacting the metal in the metal-carbon layer with a substrate containing Si driving the carbon to the surface whereby graphene is formed.
1. A method for forming a graphene layer comprising:
selecting a substrate having a first layer including carbon and a second layer including a metal over said first layer, said second layer having an upper surface,
providing an ambient, and
providing a heat treatment to said substrate in said ambient wherein said heat treatment includes heating to a temperature in the range from 550° C. to 1400° C. whereby at least some of said carbon in said first layer passes through said second layer to said upper surface and forms said graphene layer on said upper surface.
2. The method of claim 1 wherein said carbon includes sputtered carbon.
3. The method of claim 1 wherein said graphene layer on said upper surface comprises at least one of single layer graphene, few-layer graphene, multi-layer graphene, a mixture of single-layer, few-layer and multi-layer graphene, any combination of graphene layers mixed with an amorphous carbon phase and any combination of graphene layers mixed with a disordered carbon phase.
4. The method of claim 1 wherein said ambient is selected from the group consisting of vacuum, Ar/H 2 , N 2/ H 2 , N 2 , Ar, He, and mixtures thereof.
5. The method of claim 1 wherein said metal includes one or more elements selected from the group consisting of Co, Cu, Fe, Ir, Mo, Ni, Pd, Pt, Ru and alloys thereof.
6. The method of claim 1 wherein said first layer including carbon is selected from the group consisting of amorphous carbon, amorphous hydrogenated carbon containing greater than 20 atomic percent C, amorphous hydrogenated carbon containing less than 20 atomic percent H, carbon-containing polymers, carbon-containing materials comprising at least one element selected from the group consisting of Si, O, N and H and carbon-metal alloys containing less than 50 atomic percent of metal.
7. The method of claim 1 wherein said temperature is in the range from 850° C. to 1050° C.
8. The method of claim 1 wherein said first layer has a thickness in the range from 0.5 nm to 50 nm.
9. The method of claim 1 wherein said second layer has a thickness in the range from 10 nm to 5000 nm.
10. A method for forming a graphene layer comprising:
selecting a substrate having a first layer including carbon and a second layer including a metal over said first layer, said second layer having an upper surface,
providing an ambient, and providing a heat treatment to said substrate in said ambient wherein said heat treatment includes heating to a temperature in the range from 550° C. to 1400° C. whereby at least some of said carbon in said first layer passes through said second layer to said upper surface and forms said graphene layer on said upper surface wherein said metal includes Ni and alloys of Ni.
11. A method for forming a graphene layer comprising:
selecting a substrate having a first layer including carbon and a second layer including a metal over said first layer, said second layer having an upper surface,
providing an ambient, and
providing a heat treatment to said substrate in said ambient wherein said heat treatment includes heating to a temperature in the range from 550° C. to 1400° C. whereby at least some of said carbon in said first layer passes through said second layer to said upper surface and forms said graphene layer on said upper surface wherein said selected substrate further includes a third layer including a metal under said first layer.
12. A method for forming a graphene layer comprising:
selecting a substrate having a first layer including carbon and a second layer including a metal over said first layer, said second layer having an upper surface,
providing an ambient, and
providing a heat treatment to said substrate in said ambient wherein said heat treatment includes heating to a temperature in the range from 550° C. to 1400° C. whereby at least some of said carbon in said first layer passes through said second layer to said upper surface and forms said graphene layer on said upper surface wherein said carbon-containing first layer is patterned, said second layer including metal is a blanket layer.
13. A method for forming a graphene layer comprising:
selecting a substrate having a first layer including carbon and a second layer including a metal over said first layer, said second layer having an upper surface,
providing an ambient, and
providing a heat treatment to said substrate in said ambient wherein said heat treatment includes heating to a temperature in the range from 550° C. to 1400° C. whereby at least some of said carbon in said first layer passes through said second layer to said upper surface and forms said graphene layer on said upper surface wherein said carbon-containing first layer is a blanket layer, said second layer including metal is patterned.