Block copolymer patterning

The use of top-down lithographic techniques to topographically pattern substrates and thereby control the film thickness has been used to create submicron patterns that contain oriented microdomains. This approach is generally described as the graphoepitaxy method and will be discussed in further detail in Sect. 4.1, with other methods which use top-down approaches to control the bottom-up block copolymer patterns. 

Combination of Top-Down and Bottom-Up Approaches to Give Multilevel Control of Block Copolymer Patterns... 

Bottom-Up Block Copolymer Patterns Directed by Top-Down Substrate Patterns... 

The formation of bottom-up block copolymer patterns within or on top-down substrate patterns is the basis for so-called templated self-assembly processes, in which long-range order and orientation of microdomain patterns can be imposed by a template or guide . These top-down templates can take a variety of forms including periodic thickness profiles and chemically patterned surfaces. 

Park, C., Yoon, J. Thomas, E. L. Enabling nanotechnology with self assembled block copolymer patterns. Polymer 44, 6725-6760 (2003). 

Ultrafine surface chemical pattern consistent to block copolymer pattern... 

Figure 10.6 Procedure for polymer nanowire fabrication. An aqueous PEDOTtPSS solution was spin-coated on a substrate patterned with a 1.3 ym period grating, then coated with a thin Si02 layer and a PDMS homopolymer brush. A PS-PDMS block-copolymer thin film was then spin-coated and solvent-annealed. The self-assembled block-copolymer patterns were transferred into the underlying PEDOT-.PSS film through a series of reactive ion etching steps employing CF4 and O2 plasmas. (Reprinted with permission from Nano Letters, Nanowire Conductive Polymer Gas Sensor Patterned Using Self-Assembled Block Copolymer Lithography by Y. S. Jung et al., 8, 11. Copyright (2008) American Chemical Society)...

E.J.W. Crossland, Block Copolymer Patterning of Functional Materials (University of Cambridge, Cambridge, 2008)... 

Chang, J.B., Choi, H.K., Hannon, A.F., Alexander-Katz, A., Ross, C.A., Berggren, K.K., 2014. Design rules for self-assembled block copolymer patterns using tiled templates. Nat. Commun. 5. 

L. Mingqi, C. K. Ober, Block copolymer patterns and templates. Materials Today, 9, 30-39... 

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