# US 8,772,181 B2 · Method for producing graphene, graphene produced on substrate, and graphene on substrate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,181 B2 - Document ID: US8772181B2 - Status: Granted - Kind: B2 - Application number: 14/001,171 - Filed: 2012-02-27 - Published: 2013-12-26 - Granted: 2014-07-08 - Earliest claimed: 2011-02-28 - Assignees: Japan Science and Technology Agency - Applicants: Suguru Noda; Soichiro Takano - Inventors: Suguru Noda; Soichiro Takano - Web page: https://patentgrep.com/patent/US8772181B2 ## CPC - H10P 14/40: of conductive or resistive materials - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C01B 32/184: Preparation - H10D 30/031: {of thin-film transistors [TFT]} - H10D 30/6741: {Group IV materials, e.g. germanium or silicon carbide (TFTs having oxide semiconductors H10D30/6755)} - H10D 30/6758: {characterised by the insulating substrates} - H10D 64/60: Electrodes characterised by their materials - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A production method for producing graphene on a substrate, and the like are provided. According to the method, in a forming step heating is conducted to a solid solution temperature at which a solid solution of carbon dissolved in a metal is able to be formed, and a solid solution layer (505) composed of the solid solution on a substrate (103) is formed; and in a removing step graphene (102) is grown on the substrate (103) by removing the metal from the solid solution layer (505) while maintaining the heating to the solid solution temperature. As a solvent for dissolving carbon a metal composed of a single element as well as various alloys are applicable. The graphene (102) touches directly the substrate (103), by removing the metal from the solid solution layer (505) by supplying an etching gas. ## Claims ### Claim 1 A production method for graphene comprising: a forming step for forming a solid solution layer on a substrate, the solid solution layer comprising a metal in a solid state dissolving carbon, by heating to a solid solution temperature; and a removing step for growing the graphene made out of carbon precipitating from the solid solution layer, by supplying an etching gas to remove the metal from the solid solution layer while maintaining the solid solution temperature. ### Claim 2 (depends on 1) The production method according to claim 1, wherein a concentration distribution in a direction parallel to a surface of the substrate among concentration distributions of the carbon in the solid solution layer is made inhomogeneous, so as to grow the graphene in the direction parallel to the surface of the substrate. ### Claim 3 (depends on 2) A production method for graphene, wherein a line-shaped graphene grown in a first direction parallel to a surface of a substrate and directly attached to the surface is produced by the production method according to claim 2, and a planar graphene grown from the line-shaped graphene in a second direction parallel to the surface and directly attached to the surface is produced by the production method according to claim 2. ### Claim 4 (depends on 1) The production method according to claim 1, wherein in the forming step, a reducing agent that is able to reduce an oxide of the metal is supplied. ### Claim 5 (depends on 4) The production method according to claim 4, wherein in the forming step: a metallic layer comprising the metal is formed on the substrate, an initial layer comprising carbon is formed on the formed metallic layer, and the formed initial layer and the formed metallic layer are heated to the solid solution temperature to form the solid solution layer. ### Claim 6 (depends on 4) The production method according to claim 4, wherein in the forming step: an initial layer comprising a mixture of the metal and carbon is formed on the substrate, and the formed initial layer is heated to the solid solution temperature to form the solid solution layer. ### Claim 7 (depends on 4) The production method according to claim 4, wherein a concentration distribution of the supplied etching gas in a direction parallel to a surface of the substrate is made inhomogeneous, so as to grow the graphene in the direction parallel to the surface of the substrate. ### Claim 8 (depends on 4) The production method according to claim 4, wherein the substrate is a silicon dioxide substrate or a silicon substrate provided with a silicon dioxide layer on a surface, the metal is iron, nickel, cobalt, or an alloy comprising the same, and the etching gas is chlorine. ### Claim 9 (depends on 4) The production method according to claim 4, wherein in the forming step: an initial layer comprising carbon is formed on the substrate, a metallic layer comprising the metal is formed on the formed initial layer, and the formed initial layer and the formed metallic layer are heated to the solid solution temperature to form the solid solution layer. ### Claim 10 (depends on 9) The production method according to claim 9, wherein in the forming step the initial layer is formed into a predetermined pattern, so as to form the graphene in the predetermined pattern. ### Claim 11 (depends on 9) The production method according to claim 9, wherein in the forming step the initial layer is formed to cover all or a part of a surface of the substrate, so as to form the graphene into a uniform continuous film covering all or a part of the surface of the substrate. ### Claim 12 (depends on 9) The production method according to claim 9, wherein the thickness of at least one of the formed initial layer and the formed metallic layer is made inhomogeneous, so as to make a concentration distribution in a direction parallel to a surface of the substrate among concentration distributions of the carbon in the solid solution layer inhomogeneous, and to grow the graphene in the direction parallel to the surface of the substrate. ### Claim 13 (depends on 12) The production method according to claim 12, wherein the thickness of the formed metallic layer is provided with a gradient, so as to grow the graphene in the direction of a component parallel to the surface of the substrate among directions of the gradient. ### Claim 14 (depends on 13) The production method according to claim 13, wherein the metallic layer comprises a first region extending parallel over a surface of the substrate and a second region extending parallel over a surface of the substrate, the two regions being connected by a constriction, the first region having smaller thickness of the metallic layer than the second region, and the second region being provided with a gradient in the thickness of the metallic layer, which increases with the distance from the constriction.