Devices including graphene layers epitaxially grown on single crystal substrates
View Patent ↗An electronic device comprises a body including a single crystal region on a major surface of the body. The single crystal region has a hexagonal crystal lattice that is substantially lattice-matched to graphene, and a at least one epitaxial layer of graphene is disposed on the single crystal region. In a currently preferred embodiment, the single crystal region comprises multilayered hexagonal BN. A method of making such an electronic device comprises the steps of: (a) providing a body including a single crystal region on a major surface of the body. The single crystal region has a hexagonal crystal lattice that is substantially lattice-matched to graphene, and (b) epitaxially forming a at least one graphene layer on that region. In a currently preferred embodiment, step (a) further includes the steps of (a1) providing a single crystal substrate of graphite and (a2) epitaxially forming multilayered single crystal hexagonal BN on the substrate. The hexagonal BN layer has a surface region substantially lattice-matched to graphene, and step (b) includes epitaxially forming at least one graphene layer on the surface region of the hexagonal BN layer. Applications to FETs are described.
1. A device comprising:
a body including a single crystal, electrically insulative first region on a major surface of said body, said first region having a hexagonal crystal lattice substantially lattice-matched to graphene,
at least one epitaxial layer of graphene disposed on said first region of said body, and
a multi-layered, single crystal, electrically insulative second region disposed on said at least one graphene layer, said second region having a hexagonal crystal lattice within each layer thereof and being substantially lattice-matched to graphene.
2. The device of claim 1 , wherein said first region comprises a multi-layered single crystal insulator or a wide band gap semiconductor.
3. The device of claim 2 , wherein said insulator comprises single crystal hexagonal BN.
4. The device of claim 2 , wherein said body further includes a substrate of single crystal graphite, said first region being disposed on a major surface of said graphite substrate.
5. The device of claim 1 , wherein said region and said at least one graphene layer are lattice-mismatched by less than about 2%.
6. The device of claim 5 , wherein said first region and said at least one graphene layer have the same crystallographic space group.
7. A field effect transistor comprising,
a source region, a drain region, and a channel region coupling said source and drain regions to one another, and
a gate region configured to apply voltage to said channel region, thereby controlling the flow of current between said source in drain regions, and
the device of claim 1 , wherein said channel region includes a portion of said at least one grapheme layer.