Self-assembly of block copolymer thin films

Block copolymers self-assemble on nanometer length scales, making them ideal for emerging nanotechnologies. Many applications (e.g., templating, membranes) require the use of block copolymers in thin film geometries (∼100 nm thickness), where self-assembly is strongly influenced by surface energetics. In this review, we discuss the roles of surface and interfacial effects on self-assembly, with a specific focus on confinement, substrate surface modification, and thermal and solvent annealing conditions. Finally, we comment on novel techniques for manipulating and characterizing thin films, motivating the use of gradient and high-throughput methods for gaining a comprehensive picture of self-assembly to enable advanced nanotechnologies.

[1]  E. Han,et al.  Perpendicular Orientation of Domains in Cylinder-Forming Block Copolymer Thick Films by Controlled Interfacial Interactions , 2009 .

[2]  M. Matsen Thin films of block copolymer , 1997 .

[3]  Ting Xu,et al.  Highly Oriented and Ordered Arrays from Block Copolymers via Solvent Evaporation , 2004 .

[4]  George M. Whitesides,et al.  How to Make Water Run Uphill , 1992, Science.

[5]  Eun Hye Kim,et al.  Cylindrical Microdomain Orientation of PS-b-PMMA on the Balanced Interfacial Interactions: Composition Effect of Block Copolymers , 2009 .

[6]  Yongzhong Chen,et al.  Inverted to normal phase transition in solution-cast polystyrene-poly(methyl methacrylate) block copolymer thin films , 2006 .

[7]  C. Xu,et al.  Solution and Surface Composition Gradients via Microfluidic Confinement: Fabrication of a Statistical‐Copolymer‐Brush Composition Gradient , 2006 .

[8]  Yu Xuan,et al.  Morphology Development of Ultrathin Symmetric Diblock Copolymer Film via Solvent Vapor Treatment , 2004 .

[9]  C. Stafford,et al.  Nanoscopic Templates from Oriented Block Copolymer Films , 2000 .

[10]  E. Han,et al.  Cross-linked random copolymer mats as ultrathin nonpreferential layers for block copolymer self-assembly. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[11]  Craig J. Hawker,et al.  Interfacial Segregation in Disordered Block Copolymers: Effect of Tunable Surface Potentials , 1997 .

[12]  Brian C. Berry,et al.  Versatile platform for creating gradient combinatorial libraries via modulated light exposure. , 2007, The Review of scientific instruments.

[13]  S. Mochrie,et al.  Polymers on Nanoperiodic, Heterogeneous Surfaces , 1999 .

[14]  Marc A. Hillmyer,et al.  Polylactide-poly(dimethylsiloxane)-polylactide triblock copolymers as multifunctional materials for nanolithographic applications. , 2010, ACS nano.

[15]  Bumjoon J. Kim,et al.  Controlled Ordering of Block Copolymer Thin Films by the Addition of Hydrophilic Nanoparticles , 2007 .

[16]  Armin Knoll,et al.  Phase behavior in thin films of cylinder-forming ABA block copolymers: experiments. , 2004, The Journal of chemical physics.

[17]  Y. Zhang,et al.  Directed Assembly of Lamellae‐ Forming Block Copolymers by Using Chemically and Topographically Patterned Substrates , 2007 .

[18]  H. Hillhouse,et al.  Nanofabrication of Double-Gyroid Thin Films , 2007 .

[19]  B. Ocko,et al.  Salt complexation in block copolymer thin films , 2006 .

[20]  Archita Sengupta,et al.  Mesoporous Silicates Prepared Using Preorganized Templates in Supercritical Fluids , 2004, Science.

[21]  You Wang,et al.  Two-Dimensional Ordering in Block Copolymer Monolayer Thin Films upon Selective Solvent Annealing , 2008 .

[22]  V. Deline,et al.  Characteristics of the surface-induced orientation for symmetric diblock PS/PMMA copolymers , 1989 .

[23]  Craig J. Hawker,et al.  Ordered diblock copolymer films on random copolymer brushes , 1997 .

[24]  A. Knoll,et al.  Nanoscaling of microdomain spacings in thin films of cylinder-forming block copolymers. , 2007, Nano letters.

[25]  Zhiqun Lin,et al.  A Rapid Route to Arrays of Nanostructures in Thin Films , 2002 .

[26]  W. Phillip,et al.  Self-assembled block copolymer thin films as water filtration membranes. , 2010, ACS applied materials & interfaces.

[27]  R. Segalman,et al.  Block Copolymers for Organic Optoelectronics , 2009 .

[28]  Dorthe Posselt,et al.  Structural rearrangements in a lamellar diblock copolymer thin film during treatment with saturated solvent vapor. , 2010, Macromolecules.

[29]  Craig J. Hawker,et al.  Neutrality conditions for block copolymer systems on random copolymer brush surfaces , 1999 .

[30]  Kwang-Woo Kim,et al.  Transition Behavior of Block Copolymer Thin Films on Preferential Surfaces , 2008 .

[31]  Christopher Harrison,et al.  Block copolymer lithography: Periodic arrays of ~1011 holes in 1 square centimeter , 1997 .

[32]  Nicola J Ferrier,et al.  Combinatorial generation and replication-directed assembly of complex and varied geometries with thin films of diblock copolymers. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[33]  Jin Kon Kim,et al.  Block copolymer film with sponge-like nanoporous strucutre for antireflection coating. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[34]  C. Hawker,et al.  Controlling Polymer-Surface Interactions with Random Copolymer Brushes , 1997, Science.

[35]  Kenji Fukunaga,et al.  Large-Scale Alignment of ABC Block Copolymer Microdomains via Solvent Vapor Treatment , 2000 .

[36]  R. Segalman Patterning with block copolymer thin films , 2005 .

[37]  Thomas P. Russell,et al.  Solvent annealing thin films of poly (isoprene- b-lactide) , 2005 .

[38]  Adam W. Harant,et al.  Solvent vapor annealed block copolymer films on organosilane self-assembled monolayers , 2005 .

[39]  T. Iyoda,et al.  AFM Cross-Sectional Imaging of Perpendicularly Oriented Nanocylinder Structures of Microphase-Separated Block Copolymer Films by Crystal-like Cleavage , 2007 .

[40]  Brian C. Berry,et al.  Surface morphology diagram for cylinder-forming block copolymer thin films. , 2008, ACS nano.

[41]  Kathryn W. Guarini,et al.  Optimization of diblock copolymer thin film self assembly , 2002 .

[42]  Thomas H. Epps,et al.  Substrate surface energy dependent morphology and dewetting in an ABC triblock copolymer film. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[43]  P. Štěpánek,et al.  Surface patterns of block copolymers in thin layers after vapor treatment , 2007 .

[44]  Thomas P. Russell,et al.  Nanoporous Membranes with Ultrahigh Selectivity and Flux for the Filtration of Viruses , 2006 .

[45]  R. Stutz,et al.  Printing chemical gradients. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[46]  A. Knoll,et al.  Effect of confinement on the mesoscale and macroscopic swelling of thin block copolymer films. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[47]  V. Abetz,et al.  Thin Film Morphologies of ABC Triblock Copolymers Prepared from Solution , 2002 .

[48]  Paul F. Nealey,et al.  Using Self-Assembled Monolayers Exposed to X-rays To Control the Wetting Behavior of Thin Films of Diblock Copolymers , 2000 .

[49]  P. Nealey,et al.  Block copolymers and conventional lithography , 2006 .

[50]  Julie N. L. Albert,et al.  Generation of monolayer gradients in surface energy and surface chemistry for block copolymer thin film studies. , 2009, ACS nano.

[51]  E. Kramer,et al.  Wetting of Substrates with Phase-Separated Binary Polymer Mixtures , 1997 .

[52]  G. Sauer,et al.  Microdomain Morphology of Thin ABC Triblock Copolymer Films , 1999 .

[53]  Bumjoon J. Kim,et al.  Effect of Humidity on the Ordering of PEO-Based Copolymer Thin Films , 2007 .

[54]  C. Stafford,et al.  Combinatorial Mapping of the Phase Behavior of ABC Triblock Terpolymers in Thin Films: Experiments , 2005 .

[55]  A. Knoll,et al.  Phase behavior in thin films of cylinder-forming block copolymers. , 2002, Physical review letters.

[56]  G. Fredrickson,et al.  Block Copolymers—Designer Soft Materials , 1999 .

[57]  Angelika Niemz,et al.  Fabrication of nanoporous templates from diblock copolymer thin films on alkylchlorosilane-neutralized surfaces. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[58]  U. Wiesner,et al.  A bicontinuous double gyroid hybrid solar cell. , 2009, Nano letters.

[59]  M. Hillmyer,et al.  Templating Nanoporous Polymers with Ordered Block Copolymers , 2008 .

[60]  K. W. Gotrik,et al.  Generalization of the Use of Random Copolymers To Control the Wetting Behavior of Block Copolymer Films , 2008 .

[61]  Craig J. Hawker,et al.  Using Surface Active Random Copolymers To Control the Domain Orientation in Diblock Copolymer Thin Films , 1998 .

[62]  Jack F. Douglas,et al.  Combinatorial Mapping of Surface Energy Effects on Diblock Copolymer Thin Film Ordering , 2003 .

[63]  Dae-Ho Park,et al.  The fabrication of thin films with nanopores and nanogrooves from block copolymer thin films on the neutral surface of self-assembled monolayers , 2007 .

[64]  Brian C. Berry,et al.  Orientational order in block copolymer films zone annealed below the order--disorder transition temperature. , 2007, Nano letters.

[65]  R. Hayward,et al.  Crosslinked Poly(styrene)‐block‐Poly(2‐vinylpyridine) Thin Films as Swellable Templates for Mesostructured Silica and Titania , 2005 .

[66]  Kevin A. Cavicchi,et al.  Solvent Annealed Thin Films of Asymmetric Polyisoprene−Polylactide Diblock Copolymers , 2007 .

[67]  A. Mayes,et al.  Block copolymer thin films : Physics and applications , 2001 .

[68]  Zhijun Hu,et al.  Lateral nanopatterns in thin diblock copolymer films induced by selective solvents. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[69]  Kevin A. Cavicchi,et al.  Orientationally controlled nanoporous cylindrical domains in polystyrene -b -poly (ferrocenylethylmethylsilane) block copolymer films , 2007 .

[70]  Matthew Libera,et al.  Morphological Development in Solvent-Cast Polystyrene−Polybutadiene−Polystyrene (SBS) Triblock Copolymer Thin Films , 1998 .

[71]  Jan Genzer,et al.  Surface-bound soft matter gradients. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[72]  G. Brinke,et al.  Thin films of complexed block copolymers , 2009 .

[73]  E. Kramer,et al.  Graphoepitaxy of Spherical Domain Block Copolymer Films , 2001 .

[74]  E. W. Edwards,et al.  Directed Assembly of Block Copolymer Blends into Nonregular Device-Oriented Structures , 2005, Science.

[75]  M. Doi,et al.  A Transition from Cylindrical to Spherical Morphology in Diblock Copolymer Thin Films , 2008 .

[76]  G. Fredrickson,et al.  Symmetry breaking of in-plane order in confined copolymer mesophases. , 2007, Physical review letters.

[77]  G. Craig,et al.  Self-Assembly of Block Copolymers on Lithographically Defined Nanopatterned Substrates , 2007 .

[78]  F. Bates,et al.  Polymer-Polymer Phase Behavior , 1991, Science.

[79]  Caroline A. Ross,et al.  Solvent‐Vapor‐Induced Tunability of Self‐Assembled Block Copolymer Patterns , 2009 .

[80]  Richard A. Register,et al.  Orientational Order in Sphere-Forming Block Copolymer Thin Films Aligned under Shear , 2007 .

[81]  Ingemar Lundström,et al.  A wettability gradient method for studies of macromolecular interactions at the liquid/solid interface , 1987 .

[82]  Soojin Park,et al.  A simple route to highly oriented and ordered nanoporous block copolymer templates. , 2008, ACS nano.

[83]  Padma Gopalan,et al.  Side-chain-grafted random copolymer brushes as neutral surfaces for controlling the orientation of block copolymer microdomains in thin films. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[84]  E. Kramer,et al.  Square Packing and Structural Arrangement of ABC Triblock Copolymer Spheres in Thin Films , 2008 .

[85]  Craig J Hawker,et al.  A Generalized Approach to the Modification of Solid Surfaces , 2005, Science.

[86]  Paul F. Nealey,et al.  Wetting Behavior of Block Copolymers on Self-Assembled Films of Alkylchlorosiloxanes: Effect of Grafting Density , 2000 .

[87]  J F Douglas,et al.  Combinatorial study of surface pattern formation in thin block copolymer films. , 2001, Physical review letters.

[88]  E. Han,et al.  Effect of Composition of Substrate-Modifying Random Copolymers on the Orientation of Symmetric and Asymmetric Diblock Copolymer Domains , 2008 .

[89]  Thomas H. Epps,et al.  Generating thickness gradients of thin polymer films via flow coating , 2006 .

[90]  C. Hawker,et al.  Mixed Lamellar Films: Evolution, Commensurability Effects, and Preferential Defect Formation , 2000 .

[91]  Kenji Fukunaga,et al.  Symmetric diblock copolymer thin films on rough substrates. Kinetics and structure formation in pure block copolymer thin films , 2005 .

[92]  P. Guenoun,et al.  Easy Orientation of Diblock Copolymers on Self-Assembled Monolayers Using UV Irradiation , 2009, 0902.2575.

[93]  K. Shin,et al.  Morphology and Surface Relief Structures of Asymmetric Poly(styrene-block-ferrocenylsilane) Thin Films , 2001 .

[94]  Jongseung Yoon,et al.  Enabling nanotechnology with self assembled block copolymer patterns , 2003 .

[95]  Eun Hye Kim,et al.  Microdomain Orientation of PS-b-PMMA by Controlled Interfacial Interactions , 2008 .

[96]  Jin Kon Kim,et al.  Asymmetric Block Copolymers with Homopolymers: Routes to Multiple Length Scale Nanostructures , 2002 .

[97]  Gallagher,et al.  Observed surface energy effects in confined diblock copolymers. , 1996, Physical review letters.