Methods for the fabrication of graphene nanoribbon arrays using block copolymer lithography
AssigneeWisconsin Alumni Research Foundation
InventorsMichael S. Arnold, Padma Gopalan, Nathaniel S. Safron, Myungwoong Kim, Jonathan Woosun Choi
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Abstract
Methods of fabricating patterned substrates, including patterned graphene substrates, using etch masks formed from self-assembled block copolymer films are provided. Some embodiments of the methods are based on block copolymer (BCP) lithography in combination with graphoepitaxy. Some embodiments of the methods are based on BCP lithography techniques that utilize hybrid organic/inorganic etch masks derived from BCP templates. Also provided are field effect transistors incorporating graphene nanoribbon arrays as the conducting channel and methods for fabricating such transistors.
Claims16
A method of fabricating a graphene nanoribbon array, the method comprising:
- forming a graphoepitaxy channel over a graphene substrate, the channel comprising side walls and a floor;
- depositing a layer of a surface-modifying copolymer on the side walls and the floor of the channel;
- depositing a block copolymer in the channel and subjecting the block copolymer to conditions under which spatial confinement of the block copolymer by the channel induces the block copolymer to self-assemble into a plurality of domains, such that the self-assembled block copolymer layer defines a striped pattern over the graphene substrate, wherein the stripes in the striped pattern are oriented parallel with respect to the graphene substrate surface and perpendicular with respect to the channel side walls;
- and
- transferring the striped pattern into the graphene substrate to provide the graphene nanoribbon array.
A method of fabricating a patterned graphene array, the method comprising:
- depositing a block copolymer over a graphene substrate and subjecting the block copolymer to conditions that induce it to self-assemble into a plurality of polymeric domains, such that the domains define a pattern over the graphene substrate;
- converting polymeric domains in the self-assembled block copolymer into inorganic domains comprising a metal oxide, such that the inorganic domains define a pattern over the graphene substrate, by exposing the self-assembled block copolymer to metal-containing precursor molecules that coordinate selectively with a set of the polymeric domains to form initiating sites for an atomic layer deposition process and sequentially exposing the self-assembled block copolymer to oxygen-containing precursor molecules and metal-containing precursor molecules in an atomic layer deposition process, whereby metal oxide domains are grown from the selectively coordinated polymeric domains;
- and
- transferring the pattern of the inorganic domains into the graphene substrate to provide the patterned graphene array.
A method of fabricating a patterned graphene array, the method comprising:
- depositing a block copolymer over a graphene substrate and subjecting the block copolymer to conditions that induce it to self-assemble into a plurality of polymeric domains, such that the domains define a pattern over the graphene substrate;
- converting the polymeric domains in the self-assembled block copolymer into metal domains, such that the metal domains define a pattern over the graphene substrate, by selectively protonating a set of the polymeric domains;
- exposing the protonated polymeric domains to a solution comprising a metal salt, wherein the protonated polymeric domains become loaded with the metal salt via electrostatic interactions between the protonated polymeric domains and the anions of the salt;
- and exposing the metal salt-loaded domains to an oxidizing plasma, whereby a metal is formed from the metal salt;
- and
- transferring the pattern of the metal domains into the graphene substrate to provide the patterned graphene array.
Dependencies are inferred from the claim text.