Direct formation of graphene on semiconductor substrates
View Patent ↗The invention generally related to a method for preparing a layer of graphene directly on the surface of a semiconductor substrate. The method includes forming a carbon-containing layer on a front surface of a semiconductor substrate and depositing a metal film on the carbon layer. A thermal cycle degrades the carbon-containing layer, which forms graphene directly upon the semiconductor substrate upon cooling. In some embodiments, the carbon source is a carbon-containing gas, and the thermal cycle causes diffusion of carbon atoms into the metal film, which, upon cooling, segregate and precipitate into a layer of graphene directly on the semiconductor substrate.
1. A multilayer article comprising:
a semiconductor substrate comprising two major, generally parallel surfaces, one of which is a front surface of a donor substrate and the other of which is a back surface of the donor substrate, a circumferential edge joining the front and back surfaces, and a central plane between the front and back surfaces;
a layer of graphene in contact with the front surface of the semiconductor substrate; and
a metal film in contact with the layer of graphene, the metal film comprising a front metal film surface, a back metal film surface, and a bulk metal region between the front and back metal film surfaces.
2. The multilayer article of claim 1 wherein the semiconductor substrate comprises a semiconductor wafer.
3. The multilayer article of claim 2 wherein the semiconductor wafer comprises a material selected from the group consisting of silicon, gallium arsenic, silicon carbide, silicon germanium, silicon nitride, silicon dioxide, germanium, and combinations thereof.
4. The multilayer article of claim 3 wherein the semiconductor wafer comprises a silicon wafer sliced from a single crystal silicon ingot grown by the Czochralski method.
5. The multilayer article of claim 4 wherein the front surface of the semiconductor substrate comprises a dielectric layer.
6. The multilayer article of claim 4 wherein the front surface of the semiconductor substrate comprises a silicon oxide layer.
7. The multilayer article of claim 6 wherein the silicon oxide layer is between about 50 nanometers and about 1000 nanometers thick.
8. The multilayer article of claim 7 wherein the silicon oxide layer is between about 90 nanometers and about 300 nanometers thick.
9. The multilayer article of claim 1 wherein the layer of graphene in contact with the front surface of the semiconductor substrate comprises a single mono-atomic graphene layer.
10. The multilayer article of claim 1 wherein the layer of graphene in contact with the front surface of the semiconductor substrate comprises a graphene bi-layer.
11. The multilayer article of claim 1 wherein the metal film is between about 50 nanometers and about 20 micrometers thick.
12. The multilayer article of claim 1 wherein the metal film is between about 50 nanometers and about 10 micrometers thick.
13. The multilayer article of claim 1 further comprising a layer of graphene in contact with the front metal film surface.