# US 8,772,098 B2 · Transport conduits for contacts to graphene > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,098 B2 - Document ID: US8772098B2 - Status: Granted - Kind: B2 - Application number: 13/524,191 - Filed: 2012-06-15 - Published: 2013-12-19 - Granted: 2014-07-08 - Earliest claimed: 2012-06-15 - Assignees: International Business Machines Corporation - Applicants: Christos D. Dimitrakopoulos; Aaron D. Franklin; Joshua T. Smith - Inventors: Christos D. Dimitrakopoulos; Aaron D. Franklin; Joshua T. Smith - Web page: https://patentgrep.com/patent/US8772098B2 ## CPC - H10D 62/882: {Graphene} - H10D 30/481: {FETs having two-dimensional material channels, e.g. transition metal dichalcogenide [TMD] FETs} - H10D 30/6713: {characterised by the properties of the source or drain regions, e.g. compositions or sectional shapes} - H10D 30/6741: {Group IV materials, e.g. germanium or silicon carbide (TFTs having oxide semiconductors H10D30/6755)} - H10D 64/62: Electrodes ohmically coupled to a semiconductor - B82Y 40/00: Manufacture or treatment of nanostructures - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract An apparatus comprises at least one transistor. The at least one transistor comprises a substrate, a graphene layer formed on the substrate, and first and second source/drain regions spaced apart relative to one another on the substrate. The graphene layer comprises at least a first portion and a second portion, the first portion being in contact with the first source/drain region and the second portion being in contact with the second source/drain region. One or more cuts are formed in at least one of the first and second portions of the graphene layer. The apparatus allows for lowered contact resistance in graphene/metal contacts. ## Claims ### Claim 1 A method comprising: forming a graphene layer on a substrate, the graphene layer having at least a first portion and a second portion; forming one or more cuts in at least one of the first portion and the second portion; forming first and second source/drain regions spaced apart relative to one another on the substrate; wherein the first source/drain region is foamed on the first portion of the graphene layer and the second source/drain region is formed on the second portion of the graphene layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of forming the graphene layer comprises forming the graphene layer directly on the substrate. ### Claim 3 (depends on 1) The method of claim 1, wherein the step of forming the graphene layer comprises forming the graphene layer apart from the substrate and transferring the graphene layer onto the substrate. ### Claim 4 (depends on 1) The method of claim 1, wherein forming the one or more cuts comprises forming two or more cuts parallel to one another. ### Claim 5 (depends on 1) The method of claim 1, wherein forming the one or more cuts comprises forming at least one of the cuts perpendicular to a given one of first and second source/drain regions. ### Claim 6 (depends on 1) The method of claim 1, wherein the one or more cuts are formed using one of electron beam lithography, nanoimprint lithography and milling with a focused-ion beam. ### Claim 7 (depends on 1) The method of claim 1, further comprising cleaning the graphene layer to remove at least a portion of residue formed on the graphene layer as a result of forming the one or more cuts. ### Claim 8 (depends on 1) The method of claim 1, further comprising annealing the graphene layer subsequent to forming the one or more cuts. ### Claim 9 (depends on 1) The method of claim 1, wherein forming the one or more cuts comprises: forming alternating narrow lamellae of a first material and a second material on a surface of the graphene layer; and removing the narrow lamellae of the first material and at least a portion of the graphene below the lamellae of the first material using a reactive ion etching process. ### Claim 10 (depends on 9) The method of claim 9, wherein the first material is one of a block co-polymer and a polymer blend which creates self-assembled nanostructures. ### Claim 11 (depends on 1) The method of claim 1, wherein forming the one or more cuts comprises forming the one or more cuts apart relative to one another such that the cuts do not merge to form a single cut. ### Claim 12 A method, comprising: forming at least one graphene layer; forming one or more cuts in at least one portion of the graphene layer; and bonding a metal to the at least one portion of the graphene layer. ### Claim 13 (depends on 12) The method of claim 12, wherein forming the one or more cuts comprises forming two or more cuts parallel to one another. ### Claim 14 (depends on 12) The method of claim 12, wherein forming the one or more cuts comprises forming at least one of the cuts perpendicular to the metal. ### Claim 15 (depends on 12) The method of claim 12, wherein the one or more cuts are formed using one of electron beam lithography, nanoimprint lithography and milling with a focused-ion beam. ### Claim 16 (depends on 12) The method of claim 12, further comprising cleaning the graphene layer to remove at least a portion of residue formed on the graphene layer as a result of forming the one or more cuts. ### Claim 17 (depends on 12) The method of claim 12, further comprising annealing the graphene layer subsequent to forming the one or more cuts. ### Claim 18 (depends on 12) The method of claim 12, wherein forming the one or more cuts comprises: forming alternating narrow lamellae of a first material and a second material on a surface of the graphene layer; and removing the narrow lamellae of the first material and at least a portion of the graphene below the lamellae of the first material using a reactive ion etching process. ### Claim 19 (depends on 18) The method of claim 18, wherein the first material is one of a block co-polymer and a polymer blend which creates self-assembled nanostructures. ### Claim 20 (depends on 12) The method of claim 12, wherein forming the one or more cuts comprises forming the one or more cuts apart relative to one another such that the cuts do not merge to form a single cut.