Wisconsin Alumni Research Foundation

Myungwoong Kim

Padma Gopalan

Michael Scott Arnold

Nathaniel S Safron

Daniel Patrick Sweat

Eungnak Han

Xiang Yu

Jonathan Woosun Choi

Block copolymers for use in block copolymer lithography, self-assembled films of the block copolymers and methods for polymerizing the block copolymers are provided. The block copolymers are characterized by high Flory-Huggins interaction parameters (&#x3c7;). The block copolymers can be polymerized from protected hydroxystyrene monomers or from tert-butyl styrene and 2-vinylpyridine monomers.

Block copolymers with high flory-huggins interaction parameters for block copolymer lithography

Crosslinkable random copolymers comprising atom transfer radical polymerization (ATRP) initiators and crosslinked copolymer films formed from the copolymers are provided. The random copolymers, which are polymerized from one or more alkyl halide functional inimers and one or more monomers having a crosslinkable functionality, are characterized by pendant ATRP initiating groups and pendant crosslinkable groups.

Methods of making crosslinked copolymer films from inimer-containing random copolymers

Methods of producing layers of patterned graphene with smooth edges are provided. The methods comprise the steps of fabricating a layer of crystalline graphene on a surface, wherein the layer of crystalline graphene has a crystallographically disordered edge, and decreasing the crystallographic disorder of the edge of the layer of crystalline graphene by heating the layer of crystalline graphene on the surface at an elevated temperature in a catalytic environment comprising carbon-containing molecules.

Nanostructured graphene with atomically-smooth edges

Inimer-containing random copolymers and crosslinked copolymer films for dense polymer brush growth

Methods for growing microstructured and nanostructured graphene by growing the microstructured and nanostructured graphene from the bottom-up directly in the desired pattern are provided. The graphene structures can be grown via chemical vapor deposition (CVD) on substrates that are partially covered by a patterned graphene growth barrier which guides the growth of the graphene.

Barrier guided growth of microstructured and nanostructured graphene and graphite

Block copolymers with high Flory-Huggins interaction parameters for block copolymer lithography

Surface-modifying layers, including neutral layers for vertical domain-forming block copolymers of styrene and methyl methacrylate are provided. Also provided are self-assembled block copolymer structures incorporating the surface modifying layers, methods of fabricating such structures and methods of using the structures in BCP lithography applications. The surface-modifying layers comprise a crosslinked copolymer film, wherein the crosslinked copolymers are random copolymers polymerized from styrene monomers and/or (meth)acrylate monomers and crosslinkable epoxy group-functionalized monomers. The crosslinked copolymer films are characterized by a high content of the crosslinkable epoxy group-functionalized monomer.

Crosslinked random copolymer films for block copolymer domain orientation

Methods for forming a nanoperforated graphene material are provided. The methods comprise forming an etch mask defining a periodic array of holes over a graphene material and patterning the periodic array of holes into the graphene material. The etch mask comprises a pattern-defining block copolymer layer, and can optionally also comprise a wetting layer and a neutral layer. The nanoperforated graphene material can consist of a single sheet of graphene or a plurality of graphene sheets.

Methods of fabricating large-area, semiconducting nanoperforated graphene materials

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.

Methods for the fabrication of graphene nanoribbon arrays using block copolymer lithography

Block copolymer-based mask structures for the growth of patterned polymer brushes via surface-initiated atom transfer radical polymerization (SI-ATRP) are provided. Also provided are methods of making the mask structures and methods of using the mask structures to grow patterned polymer brushes. The mask structures comprise a substrate having a surface, a neutral layer comprising a crosslinked copolymer film disposed on the surface of the substrate and a domain-forming block copolymer film disposed on the crosslinked copolymer film. The crosslinked copolymer film comprises crosslinked random copolymer chains having pendant alkyl halide functional groups that are capable of acting as ATRP initiating sites.

Block copolymer-based mask structures for the growth of nanopatterned polymer brushes

Polymer films comprising crosslinked random copolymers and methods for making the films are provided. Also provided are polymer films comprising random copolymers that are covalently linked to an underlying substrate. The polymer films can be incorporated into structures in which the films are employed as surface-modifying layers for domain-forming block copolymers and the structures can be used for pattern transfer applications via block copolymer lithography. The crosslinks between the random copolymer chains in the polymer films or the links between the random copolymer chains and the substrate surface are characterized in that they can be cleaved under relatively mild conditions.

Growing community of inventors

Madison, WI, United States of America

Myungwoong Kim