Jacobberger R.MThapar VWu G.-PTZU-HSUAN CHANGSaraswat VWay A.JJinkins K.RMa ZNealey P.FHur S.-MXiong SArnold M.S.2023-06-092023-06-09202020411723https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089564952&doi=10.1038%2fs41467-020-17938-3&partnerID=40&md5=f36a78a2d18732486cf7c92832b76fdchttps://scholars.lib.ntu.edu.tw/handle/123456789/632297Directed self-assembly of block copolymers (BCPs) enables nanofabrication at sub-10 nm dimensions, beyond the resolution of conventional lithography. However, directing the position, orientation, and long-range lateral order of BCP domains to produce technologically-useful patterns is a challenge. Here, we present a promising approach to direct assembly using spatial boundaries between planar, low-resolution regions on a surface with different composition. Pairs of boundaries are formed at the edges of isolated stripes on a background substrate. Vertical lamellae nucleate at and are pinned by chemical contrast at each stripe/substrate boundary, align parallel to boundaries, selectively propagate from boundaries into stripe interiors (whereas horizontal lamellae form on the background), and register to wide stripes to multiply the feature density. Ordered BCP line arrays with half-pitch of 6.4 nm are demonstrated on stripes >80 nm wide. Boundary-directed epitaxy provides an attractive path towards assembling, creating, and lithographically defining materials on sub-10 nm scales. © 2020, The Author(s).block copolymer; copolymer; graphene; poly(propylene carbonate) block polystyrene; polystyrene; unclassified drug; chemical composition; nanoparticle; polymer; substrate; technological development; anisotropy; Article; atomic force microscopy; boundary layer; chemical feature; chemical pattern; chemical vapor deposition; crystal structure; density multiplication; dynamics; epitaxy; evolution; film thickness; immunofluorescence; incompressibility; interaction strength; kinetics; Markov chain Monte Carlo method; morphology; nanofabrication; nonhuman; orientation; oxidation; parameters; photoelectron microscopy; polymerization; robustness; scanning electron microscopy; simulation; stereolithography; superstructure; technology; temperature; tensiometry; thermodynamics; topography; X ray crystallographyjournal article10.1038/s41467-020-17938-3328147752-s2.0-85089564952