METHOD FOR PRODUCING A GRAPHENE NANO-RIBBON
A method for producing a graphene nanoribbon is disclosed. This production method includes the steps of: forming a crystalline catalytic metal layer composed of copper or nickel on a (110) plane or a (112) plane of a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate, with a thickness of the crystalline catalytic metal layer being controlled and with a crystal orientation of the crystalline catalytic metal layer being controlled so that the crystal orientation coincides with a crystal orientation of the single-crystal substrate; forming a cap layer composed of an oxide on the formed catalytic metal layer; exposing a {111} plane of the crystalline catalytic metal layer as a side wall by etching a stack including the substrate, the catalytic metal layer, and the cap layer; and growing graphene selectively on the exposed side wall by chemical vapor deposition.
1 . A method for producing a graphene nanoribbon, comprising the steps of:
forming a crystalline catalytic metal layer composed of copper or nickel on a (110) plane or a (112) plane of a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate, with a thickness of the crystalline catalytic metal layer being controlled and with a crystal orientation of the crystalline catalytic metal layer being controlled so that the crystal orientation coincides with a crystal orientation of the single-crystal substrate;
forming a cap layer composed of an oxide on the formed catalytic metal layer;
exposing a {111} plane of the crystalline catalytic metal layer as a side wall by etching a stack including the substrate, the catalytic metal layer, and the cap layer; and
growing graphene selectively on the exposed side wall by chemical vapor deposition.
2 . A method for producing a graphene nanoribbon, comprising the steps of:
forming a crystalline catalytic metal layer composed of copper or nickel on a (110) plane or a (112) plane of a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate, with a thickness of the crystalline catalytic metal layer being controlled and with a crystal orientation of the crystalline catalytic metal layer being controlled so that the crystal orientation coincides with a crystal orientation of the single-crystal substrate;
forming at least one pair of a crystalline spacer layer composed of MgAl 2 O 4 and an additional crystalline catalytic metal layer that are stacked in this order on the formed catalytic metal layer, with control of a crystal orientation of the spacer layer, a thickness of the additional catalytic metal layer, and a crystal orientation of the additional catalytic metal layer;
forming a cap layer composed of an oxide on a stack including the substrate, the catalytic metal layer, the spacer layer, and the additional catalytic metal layer;
exposing a (111) plane of at least one layer selected from the catalytic metal layer and the additional catalytic metal layer as a side wall by etching the stack; and
growing graphene selectively on the exposed side wall by chemical vapor deposition, wherein
the control of the crystal orientations of the spacer layer and the additional catalytic metal layer is carried out so that the crystal orientation of the spacer layer coincides with the crystal orientation of the catalytic metal layer underlying said spacer layer, and that the crystal orientation of the additional catalytic metal layer coincides with the crystal orientation of the spacer layer underlying said additional catalytic metal layer.
3 . A method for producing a graphene nanoribbon, comprising the steps of:
forming a layer composed of copper or nickel on a (110) plane or a (112) plane of a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate, with a thickness of the layer being controlled and with a crystal orientation of the layer being controlled so that the crystal orientation coincides with a crystal orientation of the single-crystal substrate;
forming a cap layer composed of an oxide on the formed layer composed of copper or nickel;
exposing a {111} plane of the layer composed of copper or nickel as a side wall by etching a side surface of the layer; and
growing graphene selectively on the exposed side wall.
4 . A method for producing a graphene nanoribbon, comprising the steps of:
forming a layer composed of copper or nickel on a (110) plane or a (112) plane of a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate, with a thickness of the layer being controlled and with a crystal orientation of the layer being controlled so that the crystal orientation coincides with a crystal orientation of the single-crystal substrate;
forming, on the formed layer composed of copper or nickel, at least one pair of a MgAl 2 O 4 single-crystal layer and a layer composed of copper or nickel that are stacked in this order;
forming a cap layer composed of an oxide on a stack including the substrate, the layer composed of copper or nickel, and the MgAl 2 O 4 single-crystal layer;
exposing a {111} plane of the layer composed of copper or nickel as a side wall by etching a side surface of the layer; and
growing graphene selectively on the exposed side wall.
5 . A method for producing a graphene nanoribbon, comprising the steps of:
preparing a stack including: a MgAl 2 O 4 single-crystal substrate or a MgO single-crystal substrate; and a layer formed on the substrate and composed of copper or nickel, the stack including a {111} plane as a plane perpendicular to a principal surface of the layer;
exposing a {111} plane of the layer composed of copper or nickel as a side wall; and
growing graphene on the exposed side wall.
6 . A method for producing a transistor, comprising the step of forming a transistor using the graphene nanoribbon obtained by the production method according to claim 1 as a channel.