[1] Semiconductor Industry Association 2019 2015 International technology roadmap for semiconductors (ITRS) (www.semiconductors.org/resources/2015-internationaltechnology- roadmap-for-semiconductors-itrs/)

[2] Wu B Q and Kumar A 2014 Extreme ultraviolet lithography and three dimensional integrated circuit—a review Appl. Phys. Rev. 1 011104

[3] Wack D C et al 2008 Opportunities and challenges for optical CD metrology in double patterning process control Proc. SPIE 6922 69221N

[4] Chen Y F 2015 Nanofabrication by electron beam lithography and its applications: a review Microelectron. Eng. 135 57–72

[5] Wei Y Y, Zhao C and Ye T C 2014 Analysis of mix-and-match litho approach for manufacturing 20NM logic-node products Proc. SPIE 9049 90491Y

[6] Bates F S and Fredrickson G H 1999 Block copolymers—designer soft materials Phys. Today 52 32–38

[7] Li W H and Müller M 2016 Directed self-assembly of block copolymers by chemical or topographical guiding patterns: optimizing molecular architecture, thin-film properties, and kinetics Prog. Polym. Sci. 54–5 47–75

[8] IRDS 2019 IEEE international roadmap for devices and systems 2017 edition (https://irds.ieee.org/roadmap-2017)

[9] Mansky P, Haikin P and Thomas E L 1995 Monolayer films of diblock copolymer microdomains for nanolithographic applications J. Mater. Sci. 30 1987–92

[10] Mansky P, Russell T P, Hawker C J, Pitsikalis M and Mays J 1997 Ordered diblock copolymer films on random copolymer brushes Macromolecules 30 6810–3

[11] Segalman R A, Yokoyama H and Kramer E J 2001 Graphoepitaxy of spherical domain block copolymer films Adv. Mater. 13 1152–5

[12] Kim S O, Solak H H, Stoykovich M P, Ferrier N J, de Pablo J and Nealey P F 2003 Epitaxial self-assembly of block copolymers on lithographically defined nanopatterned substrates Nature 424 411–4

[13] Jeong S J, Kim J Y, Kim B H, Moon H S and Kim S O 2013 Directed self-assembly of block copolymers for next generation nanolithography Mater. Today 16 468–76

[14] Sinturel C, Bates F S and Hillmyer M A 2015 High χ–low N block polymers: how far can we go? ACS Macro Lett. 4 1044–50

[15] Xiong S S, Wan L, Ishida Y, Chapuis Y A, Craig G S W, Ruiz R and Nealey P F 2016 Directed self-assembly of triblock copolymer on chemical patterns for sub-10-nm nanofabrication via solvent annealing ACS Nano 10 7855–65

[16] Yang G W and Wu G P 2019 High-efficiency construction of CO2-based healable thermoplastic elastomers via a tandem synthetic strategy ACS Sustain. Chem. Eng. 7 1372–80

[17] Cummins C, Kelly R A, Gangnaik A, Georgiev Y M, Petkov N, Holmes J D and Morris M A 2015 Solvent vapor annealing of block copolymers in confined topographies: commensurability considerations for nanolithography Macromol. Rapid Commun. 36 762–7

[18] Kim E, Park S, Han Y S and Kim T H 2018 Effect of solvent selectivity on supramolecular assemblies of block copolymer by solvent-vapor annealing Polymer 150 214–22

[19] Rasappa S, Hulkkonen H, Schulte L, Ndoni S, Reuna J, Salminen T and Niemi T 2019 High molecular weight block copolymer lithography for nanofabrication of hard mask and photonic nanostructures J. Colloid Interface Sci. 534 420–9

[20] Maher M J et al 2014 Interfacial design for block copolymer thin films Chem. Mater. 26 1471–9

[21] Jin C, Murphy J N, Harris K D and Buriak J M 2014 Deconvoluting the mechanism of microwave annealing of block copolymer thin films ACS Nano 8 3979–91

[22] Rincon Delgadillo P A et al 2012 All track directed self-assembly of block copolymers: process flow and origin of defects Proc. SPIE 8323 83230D

[23] Rathsack B et al 2013 Advances in directed self assembly integration and manufacturability at 300 mm Proc. SPIE 8682 86820K

[24] Hirahara E et al 2016 Directed self-assembly materials for high resolution beyond PS-b-PMMA J. Photopolym. Sci. Technol. 29 679–84

[25] Wan L, Ruiz R, Gao H, Patel K C, Albrecht T R, Yin J, Kim J, Cao Y and Lin G 2015 The limits of lamellae-forming PS-b-PMMA block copolymers for lithography ACS Nano 9 7506–14

[26] Zhang J Q et al 2014 New materials for directed self-assembly for advanced patterning Proc. SPIE 9051 905111

[27] Kihara N et al 2015 Sub-10-nm patterning process using directed self-assembly with high χ block copolymers J. Micro/Nanolith. Microfab. Microsyst. 14 023502

[28] Vora A, Chunder A, Tjio M, Magbitang T, Lofano E, Arellano N, Schmidt K, Nguyen K, Cheng J and Sanders D P 2015 Synthesis and characterization of polycarbonate-containing all-organic high-χ block copolymers for directed self-assembly J. Photopolym. Sci. Technol. 28 659–62

[29] Vora A, Alva G, Chunder A, Schmidt K, Magbitang T, Lofano E, Arellano N, Cheng J and Sanders D P 2016 Synthesis and thin-film self-assembly of cylinder-forming high-χ block copolymers J. Photopolym. Sci. Technol. 29 685–8

[30] Vora A, Wojtecki R J, Schmidt K, Chunder A, Cheng J Y, Nelson A and Sanders D P 2016 Development of polycarbonate-containing block copolymers for thin film self-assembly applications Polym. Chem. 7 940–50

[31] Zhang X S, He Q B, Chen Q, Nealey P F and Ji S X 2018 Directed self-assembly of high χ poly(styrene-b-(lactic acid-alt-glycolic acid)) block copolymers on chemical patterns via thermal annealing ACS Macro Lett. 7 751–6

[32] Jo S, Jeon S, Jun T, Park C and Ryu D Y 2018 Fluorine-containing styrenic block copolymers toward high χ and perpendicular lamellae in thin films Macromolecules 51 7152–9

[33] Lane A P, Yang X M, Maher M J, Blachut G, Asano Y, Someya Y, Mallavarapu A, Sirard S M, Ellison C J and Willson C G 2017 Directed self-assembly and pattern transfer of five nanometer block copolymer lamellae ACS Nano 11 7656–65

[34] Pang Y Y, Jin X S, Huang G C, Wan L and Ji S X 2019 Directed self-assembly of styrene-methyl acrylate block copolymers with sub-7 nm features via thermal annealing Macromolecules 52 2987–94

[35] Son J G, Hannon A F, Gotrik K W, Alexander-Katz A and Ross C A 2011 Hierarchical nanostructures by sequential self-assembly of styrene-dimethylsiloxane block copolymers of different periods Adv. Mater. 23 634–9

[36] Cheng L C, Bai W B, Fernandez Martin E, Tu K H, Ntetsikas K, Liontos G, Avgeropoulos A and Ross C A 2017 Morphology, directed self-assembly and pattern transfer from a high molecular weight polystyrene-block-poly(dimethylsiloxane) block copolymer film Nanotechnology 28 145301

[37] Jeong J W, Park W I, Kim M J, Ross C A and Jung Y S 2011 Highly tunable self-assembled nanostructures from a poly(2-vinylpyridine-b-dimethylsiloxane) block copolymer Nano Lett. 11 4095–101

[38] Azuma K, Sun J, Choo Y, Rokhlenko Y, Dwyer J H, Schweitzer B, Hayakawa T, Osuji C O and Gopalan P 2018 Self-assembly of an ultrahigh-χ block copolymer with versatile etch selectivity Macromolecules 51 6460–7

[39] Maher M J, Rettner C T, Bates C M, Blachut G, Carlson M C, Durand W J, Ellison C J, Sanders D P, Cheng J Y and Willson C G 2015 Directed self-assembly of silicon-containing block copolymer thin films ACS Appl. Mater. Interfaces 7 3323–8

[40] Nakatani R et al 2017 Perpendicular orientation control without interfacial treatment of RAFT-synthesized high-χ block copolymer thin films with sub-10 nm features prepared via thermal annealing ACS Appl. Mater. Interfaces 9 31266–78

[41] Kim S H, Misner M J, Xu T, Kimura M and Russell T P 2004 Highly oriented and ordered arrays from block copolymers via solvent evaporation Adv. Mater. 16 226–31

[42] Jung Y S and Ross C A 2009 Solvent-vapor-induced tunability of self-assembled block copolymer patterns Adv. Mater. 21 2540–5

[43] Lundy R, Flynn S P, Cummins C, Kelleher S M, Collins M N, Dalton E, Daniels S, Morris M A and Enright R 2017 Controlled solvent vapor annealing of a high χ block copolymer thin film Phys. Chem. Chem. Phys. 19 2805–15

[44] Nelson G, Drapes C S, Grant M A, Gnabasik R, Wong J and Baruth A 2018 High-precision solvent vapor annealing for block copolymer thin films Micromachines 9 271

[45] Bai W, Yager K G and Ross C A 2015 In situ characterization of the self-assembly of a polystyrene–polydimethylsiloxane block copolymer during solvent vapor annealing Macromolecules 48 8574–84

[46] Park S, Lee D H, Xu J, Kim B, Hong S W, Jeong U, Xu T and Russell T P 2009 Macroscopic 10-terabit–per–square-inch arrays from block copolymers with lateral order Science 323 1030–3

[47] Tada Y, Yoshida H, Ishida Y, Hirai T, Bosworth J K, Dobisz E, Ruiz R, Takenaka M, Hayakawa T and Hasegawa H 2012 Directed self-assembly of POSS containing block copolymer on lithographically defined chemical template with morphology control by solvent vapor Macromolecules 45 292–304

[48] Bosworth J K, Dobisz E and Ruiz R 2010 20 nm pitch directed block copolymer assembly using solvent annealing for bit patterned media J. Photopolym. Sci. Technol. 23 145–8

[49] Chavis M A, Smilgies D M, Wiesner U B and Ober C K 2015 Widely tunable morphologies in block copolymer thin films through solvent vapor annealing using mixtures of selective solvents Adv. Funct. Mater. 25 3057–65

[50] Sun Z W et al 2015 Directed self-assembly of poly(2- vinylpyridine)-b-polystyrene-b-poly(2-vinylpyridine) triblock copolymer with sub-15 nm spacing line patterns using a nanoimprinted photoresist template Adv. Mater. 27 4364–70

[51] Xiong S S, Li D X, Hur S M, Craig G S W, Arges C G, Qu X-P and Nealey P F 2018 The solvent distribution effect on the self-assembly of symmetric triblock copolymers during solvent vapor annealing Macromolecules 51 7145–51

[52] Seshimo T, Bates C M, Dean L M, Cushen J D, Durand W J, Maher M J, Ellison C J and Willson C G 2012 Block copolymer orientation control using a top-coat surface treatment J. Photopolym. Sci. Technol. 25 125–30

[53] Bates C M, Seshimo T, Maher M J, Durand W J, Cushen J D, Dean L M, Blachut G, Ellison C J and Willson C G 2012 Polarity-switching top coats enable orientation of sub–10-nm block copolymer domains Science 338 775–9

[54] Suh H S, Kim D H, Moni P, Xiong S S, Ocola L E, Zaluzec N J, Gleason K K and Nealey P F 2017 Sub-10-nm patterning via directed self-assembly of block copolymer films with a vapour-phase deposited topcoat Nat. Nanotechnol. 12 575–81

[55] Jiang J, Jacobs A G, Wenning B, Liedel C, Thompson M O and Ober C K 2017 Ultrafast self-assembly of sub-10 nm block copolymer nanostructures by solvent-free high-temperature laser annealing ACS Appl. Mater. Interfaces 9 31317–24

[56] Borah D, Senthamaraikannan R, Rasappa S, Kosmala B, Holmes J D and Morris M A 2013 Swift nanopattern formation of PS-b-PMMA and PS-b-PDMS block copolymer films using a microwave assisted technique ACS Nano 7 6583–96

[57] Son J G, Chang J B, Berggren K K and Ross C A 2011 Assembly of sub-10-nm block copolymer patterns with mixed morphology and period using electron irradiation and solvent annealing Nano Lett. 11 5079–84

[58] Mickiewicz R A, Yang J K W, Hannon A F, Jung Y S, Alexander-Katz A, Berggren K K and Ross C A 2010 Enhancing the potential of block copolymer lithography with polymer self-consistent field theory simulations Macromolecules 43 8290–5

[59] Li W H and Müller M 2016 Thermodynamics and kinetics of defect motion and annihilation in the self-assembly of lamellar diblock copolymers Macromolecules 49 6126–38

[60] Khaira G S, Qin J, Garner G P, Xiong S S, Wan L, Ruiz R, Jaeger H M, Nealey P F and de Pablo J J 2014 Evolutionary optimization of directed self-assembly of triblock copolymers on chemically patterned substrates ACS Macro Lett 3 747–52

[61] Liu C C et al 2013 Chemical patterns for directed self-assembly of lamellae-forming block copolymers with density multiplication of features Macromolecules 46 1415–24

[62] Hur S M, Khaira G S, Ramírez-Hern′andez A, Müller M, Nealey P F and de Pablo J J 2015 Simulation of defect reduction in block copolymer thin films by solvent annealing ACS Macro Lett. 4 11–5

[63] Jeong U, Kim H C, Rodriguez R L, Tsai I Y, Stafford C M, Kim J K, Hawker C J and Russell T P 2002 Asymmetric block copolymers with homopolymers: routes to multiple length scale nanostructures Adv. Mater. 14 274–6

[64] Shin K, Amanda Leach K, Goldbach J T, Kim D H, Young Jho J, Tuominen M, Hawker C J and Russell T P 2002 A simple route to metal nanodots and nanoporous metal films Nano Lett. 2 933–6

[65] Peng Q, Tseng Y C, Darling S B and Elam J W 2010 Nanoscopic patterned materials with tunable dimensions via atomic layer deposition on block copolymers Adv. Mater. 22 5129–33

[66] Gu X D, Gunkel I and Russell T P 2013 Pattern transfer using block copolymers Philos. Trans. R. Soc. A 371 20120306

[67] Jung Y S and Ross C A 2007 Orientation-controlled self-assembled nanolithography using a polystyrene?polydimethylsiloxane block copolymer Nano Lett. 7 2046–50

[68] Aissou K, Mumtaz M, Fleury G, Portale G, Navarro C, Cloutet E, Brochon C, Ross C A and Hadziioannou G 2015 Sub-10 nm features obtained from directed self-assembly of semicrystalline polycarbosilane-based block copolymer thin films Adv. Mater. 27 261–5

[69] Tu K H, Bai W B, Liontos G, Ntetsikas K, Avgeropoulos A and Ross C A 2015 Universal pattern transfer methods for metal nanostructures by block copolymer lithography Nanotechnology 26 375301

[70] Lammertink R G H, Hempenius M A, Chan V Z H, Thomas E L and Vancso G J 2001 Poly(ferrocenyldimethylsilanes) for reactive ion etch barrier applications Chem. Mater. 13 429–34

[71] Flynn S P et al 2018 Nitrogen reactive ion etch processes for the selective removal of poly-(4-vinylpyridine) in block copolymer films Nanotechnology 29 355302

[72] Tseng Y C, Peng Q, Ocola L E, Elam J W and Darling S B 2011 Enhanced block copolymer lithography using sequential infiltration synthesis J. Phys. Chem. C 115 17725–9

[73] Peng Q, Tseng Y C, Darling S B and Elam J W 2011 A route to nanoscopic materials via sequential infiltration synthesis on block copolymer templates ACS Nano 5 4600–6

[74] Yang G W, Wu G P, Chen X X, Xiong S S, Arges C G, Ji S, Nealey P F, Lu X-B, Darensbourg D J and Xu Z-K 2017 Directed self-assembly of polystyrene-b-poly(propylene carbonate) on chemical patterns via thermal annealing for next generation lithography Nano Lett. 17 1233–9

[75] Ishchenko O M, Krishnamoorthy S, Valle N, Guillot J, Turek P, Fechete I and Lenoble D 2016 Investigating sequential vapor infiltration synthesis on block-copolymer-templated titania nanoarrays J. Phys. Chem. C 120 7067–76

[76] Peng Q, Tseng Y C, Long Y, Mane A U, DiDona S, Darling S B and Elam J W 2017 Effect of nanostructured domains in self-assembled block copolymer films on sequential infiltration synthesis Langmuir 33 13214–23

[77] Biswas M, Libera J A, Darling S B and Elam J W 2014 New insight into the mechanism of sequential infiltration synthesis from infrared spectroscopy Chem. Mater. 26 6135–41

[78] Lorenzoni M, Evangelio L, Fern′andez-Reg′ulez M, Nicolet C, Navarro C and P′erez-Murano F 2017 Sequential infiltration of self-assembled block copolymers: a study by atomic force microscopy J. Phys. Chem. C 121 3078–86

[79] Frascaroli J, Cianci E, Spiga S, Seguini G and Perego M 2016 Ozone-based sequential infiltration synthesis of Al2O3 nanostructures in symmetric block copolymer ACS Appl. Mater. Interfaces 8 33933–42

[80] Xiao S G, Yang X M, Lee K Y, Ver Der Veerdonk R J M, Kuo D and Russell T P 2011 Aligned nanowires and nanodots by directed block copolymer assembly Nanotechnology 22 305302

[81] Hong A J, Liu C C, Wang Y, Kim J, Xiu F X, Ji S, Zou J, Nealey P F and Wang K L 2010 Metal nanodot memory by self-assembled block copolymer lift-off Nano Lett. 10 224–9

[82] Jung Y S, Lee J H, Lee J Y and Ross C A 2010 Fabrication of diverse metallic nanowire arrays based on block copolymer self-assembly Nano Lett. 10 3722–6

[83] Kim Y C and Kim S Y 2018 Fabrication of gold nanowires in micropatterns using block copolymers RSC Adv. 8 19532–8

[84] Huang Y G et al 2013 InAs nanowires grown by metal–organic vapor-phase epitaxy (MOVPE) employing PS/PMMA diblock copolymer nanopatterning Nano Lett. 13 5979–84

[85] Arias-Zapata J, Garnier J D, Mehedi H A, Legrain A, Salem B, Cunge G and Zelsmann M 2019 Engineering self-assembly of a high-χ block copolymer for large-area fabrication of transistors based on functional graphene nanoribbon arrays Chem. Mater. 31 3154–62

[86] Jin C, Olsen B C, Luber E J and Buriak J M 2017 Nanopatterning via solvent vapor annealing of block copolymer thin films Chem. Mater. 29 176–88

[87] Yoshimura Y, Chandra A, Nabae Y and Hayakawa T 2019 Chemically tailored high-χ block copolymers for perpendicular lamellae via thermal annealing Soft Matter 15 3497–506

[88] Somervell M et al 2012 Comparison of directed self-assembly integrations Proc. SPIE 8325 83250G

[89] Bita I, Yang J K W, Jung Y S, Ross C A, Thomas E L and Berggren K K 2008 Graphoepitaxy of self-assembled block copolymers on two-dimensional periodic patterned templates Science 321 939–43

[90] Liu C C, Thode C J, Rincon Delgadillo P A, Craig G S W, Nealey P F and Gronheid R 2011 Towards an all-track 300 mm process for directed self-assembly J. Vac. Sci. Technol. B 29 06F203

[91] Rincon Delgadillo P A et al 2012 Implementation of a chemo-epitaxy flow for directed self-assembly on 300-mm wafer processing equipment J. Micro/Nanolith. Microfab. Microsyst. 11 031302

[92] Rincon Delgadillo P A et al 2013 Process sensitivities in exemplary chemo-epitaxy directed self-assembly integration Proc. SPIE 8680 86801H

[93] Gronheid R, Rincon Delgadillo P, Singh A, Younkin T R, Suyan S, Chan B T, Van Look L, Bekaert J, Pollentir I and Nealey P F 2013 Readying directed self-assembly for patterning in semi-conductor manufacturing J. Photopolym. Sci. Technol. 26 779–91

[94] Rincon Delgadillo P A, Gronheid R, Thode C J, Wu H P, Cao Y, Lin G, Somervell M, Nafus K and Nealey P F 2012 Geometric control of chemically nano-patterned substrates for feature multiplication using directed self-assembly of block copolymers J. Photopolym. Sci. Technol. 25 77–81

[95] Rincon Delgadillo P et al 2013 Defect source analysis of directed self-assembly process (DSA of DSA) Proc. SPIE 8680 86800L

[96] Gronheid R et al 2014 Defect reduction and defect stability in IMEC’s 14nm half-pitch chemo-epitaxy DSA flow Proc. SPIE 9049 904905

[97] Ito C et al 2014 Inspection of directed self-assembly defects Proc. SPIE 9049 90492D

[98] Pathangi H et al 2015 Defect mitigation and root cause studies in 14 nm half-pitch chemo-epitaxy directed self-assembly LiNe flow J. Micro/Nanolith. Microfab. Microsyst. 14 031204

[99] Muramatsu M, Nishi T, You G, Ido Y and Kitano T 2018 Defect and roughness reduction of chemo-epitaxy DSA pattern Proc.SPIE 10584 105840M

[100] Weng M H et al 2018 Directed self-assembly (DSA) for contact applications Proc. SPIE 10586 105861D

[101] Zhou C et al 2018 Studying the effects of chemistry and geometry on DSA hole-shrink process in three-dimensions J. Micro/Nanolith. Microfab. Microsyst. 17 031203

[102] Younkin T R et al 2013 Progress in directed self-assembly hole shrink applications Proc. SPIE 8682 86820L

[103] Gronheid R et al 2013 Rectification of EUV-patterned contact holes using directed self-assembly Proc. SPIE 8682 86820A

[104] Tiron R et al 2015 Contact hole shrink and multiplication by directed self-assembly of block copolymers: from material to integration MRS Proc. 1750 mrsf14-1750-kk04-03

[105] Rathsack B et al 2012 Pattern scaling with directed self assembly through lithography and etch process integration Proc. SPIE 8323 83230B

[106] Ko T H, Lo K H, Wu C H, Chang C Y, Lee C J and Lin J 2016 Defectivity study for directed self-assembly (DSA) contact hole shrink J. Photopolym. Sci. Technol. 29 793–6

[107] Guillorn M et al 2008 FinFET performance advantage at 22 nm: an AC perspective Proc. 2008 Symp. on VLSI Technology (Honolulu, HI: IEEE) pp 12–3

[108] Tsai H et al 2014 Two-dimensional pattern formation using graphoepitaxy of PS-b-PMMA block copolymers for advanced FinFET device and circuit fabrication ACS Nano 8 5227–32

[109] Liu C C et al 2018 Directed self-assembly of block copolymers for 7 nanometre FinFET technology and beyond Nat. Electron. 1 562–9

[110] Sayan S et al 2016 Toward sub-20 nm pitch Fin patterning and integration with DSA Proc. SPIE 9779 97790R

[111] Mitra J, Torres A and Pan D Z 2017 Process, design rule, and layout co-optimization for DSA based patterning of sub-10 nm Finfet devices Proc. SPIE 10144 101440G

[112] Lai K F et al 2017 Design technology co-optimization assessment for directed self-assembly-based lithography: design for directed self-assembly or directed self-assembly for design? J. Micro/Nanolith. Microfab. Microsyst. 16 013502

[113] Park W I, You B K, Mun B H, Seo H K, Lee J Y, Hosaka S, Yin Y, Ross C A, Lee K J and Jung Y S 2013 Self-assembled incorporation of modulated block copolymer nanostructures in phase-change memory for switching power reduction ACS Nano 7 2651–8

[114] You B K, Park W I, Kim J M, Park K I, Seo H K, Lee J Y, Jung Y S and Lee K J 2014 Reliable control of filament formation in resistive memories by self-assembled nanoinsulators derived from a block copolymer ACS Nano 8 9492–502

[115] Chen H Y et al 2017 Resistive random access memory (RRAM) technology: from material, device, selector, 3D integration to bottom-up fabrication J. Electroceram. 39 21–38

[116] Frascaroli J, Brivio S, Ferrarese Lupi F, Seguini G, Boarino L, Perego M and Spiga S 2015 Resistive switching in high-density nanodevices fabricated by block copolymer self-assembly ACS Nano 9 2518–29

[117] Albrecht T R et al 2015 Bit-patterned magnetic recording: theory, media fabrication, and recording performance IEEE Trans. Magn. 51 0800342

[118] Ji S X, Wan L, Liu C C and Nealey P F 2016 Directed self-assembly of block copolymers on chemical patterns: a platform for nanofabrication Prog. Polym. Sci. 54–5 76–127

[119] Xiao S G, Yang X M, Steiner P, Hsu Y, Lee K, Wago K and Kuo D 2014 Servo-integrated patterned media by hybrid directed self-assembly ACS Nano 8 11854–9

[120] Yang X M, Xiao S G, Hu W, Hwu J, Van De Veerdonk R, Wago K, Lee K and Kuo D 2014 Integration of nanoimprint lithography with block copolymer directed self-assembly for fabrication of a sub-20 nm template for bit-patterned media Nanotechnology 25 395301

[121] Yang X M et al 2014 Fabrication of servo-integrated template for 1.5 Teradot/inch2 bit patterned media with block copolymer directed assembly J. Micro/Nanolith. Microfab. Microsyst. 13 031307

[122] Doerk G S, Gao H, Wan L, Lille J, Patel K C, Chapuis Y-A, Ruiz R and Albrecht T R 2015 Transfer of self-aligned spacer patterns for single-digit nanofabrication Nanotechnology 26 085304

[123] Xiong S, Chapuis Y A, Wan L, Gao H, Li X, Ruiz R and Nealey P F 2016 Directed self-assembly of high-chi block copolymer for nano fabrication of bit patterned media via solvent annealing Nanotechnology 27 415601

[124] Hulkkonen H H, Salminen T and Niemi T 2017 Block copolymer patterning for creating porous silicon thin films with tunable refractive indices ACS Appl. Mater. Interfaces 9 31260–5

[125] Mokarian-Tabari P, Senthamaraikannan R, Glynn C, Collins T, Cummins C, Nugent D, O’Dwyer C and Morris M A 2017 Large block copolymer self-assembly for fabrication of subwavelength nanostructures for applications in optics Nano Lett. 17 2973–8

[126] Rasappa S, Schulte L, Ndoni S and Niemi T 2018 Directed self-assembly of a high-chi block copolymer for the fabrication of optical nanoresonators Nanoscale 10 18306–14