Double-Layer Morphologies from a Silicon-Containing ABA Triblock Copolymer

Abstract

A combined experimental and self-consistent-field theoretical (SCFT) investigation of the phase behavior of poly(stryrene- b-dimethylsiloxane- b-styrene) (PS- b-PDMS- b-PS, or SDS32) thin films during solvent vapor annealing is presented. The morphology of the triblock copolymer is described as a function of the as-cast film thickness and the ratio of two different solvent vapors, toluene and heptane. SDS32 formed terraced bilayer morphologies even when the film thickness was much lower than the commensurate thickness. The morphology transitioned between bilayer cylinders, bilayer perforated lamellae, and bilayer lamellae, including mixed structures such as a perforated lamella on top of a layer of in-plane cylinders, as the heptane fraction during solvent annealing increased. SCFT modeling showed the same morphological trends as a function of the block volume fraction. In comparison with diblock PS- b-PDMS with the same molecular weight, the SDS32 offers a simple route to produce a diversity of well-ordered bilayer structures with smaller feature sizes, including the formation of bilayer perforated lamellae over a large process window.

Selective Deposition of Copper on Self-Assembled Block Copolymer Surfaces via Physical Vapor Deposition

“…Block copolymer (BCP) self-assemblya facile, scalable, and cost-effective way of producing a cornucopia of periodic arrays at a nanometer length scalehas been leveraged to overcome the limitations of conventional lithography. − Directed self-assembly of BCPs in particular allows for density multiplication of patterns in long-range order and generation of a variety of geometries ranging from close-packed dots or lines to more complex features such as rectilinear arrays, line segments, or lines with bends, junctions, jogs, and so on. − However, a majority of practical applications that could benefit from such well-ordered BCP nanopatterns require the functionality of metals, semiconductors, or dielectrics instead of polymeric materials. − Hence, pattern transfer from self-assembled BCPs into other materials is critically important to provide nanostructures with desired properties.…”

Resolving Triblock Terpolymer Morphologies by Vapor-Phase Infiltration

“…[1][2][3][4][5][6] Self-assembly of block copolymer (BCP) thin films in particular offers an efficient route to produce a variety of 3D nanostructures, taking advantage of its simple sequence of processing steps. [7][8][9][10][11][12][13][14] Compared with diblock copolymers, triblock and multiblock polymers can produce nanostructures with greater structural diversity and additional chemical functionalities, [15][16][17][18][19][20] and there has been an increasing emphasis on understanding their selfassembly and 3D morphologies. [21][22][23][24][25] However, it is challenging to resolve the morphologies of 3D BCPs comprising more than two polymeric components unless there is good contrast between the microdomains, for example a contrast in density, chemical composition, or reactivity.…”

Vertical Lamellae Formed by Two-Step Annealing of a Rod–Coil Liquid Crystalline Block Copolymer Thin Film

“…BCP nanofabrication strategies are often based on pattern transfer from the BCP via etching processes, and thus BCP materials with one or more etch-resistant blocks are good candidates . Silicon-containing BCPs (Si-BCPs) comprising blocks such as PDMS (polydimethylsiloxane), PFS (polyferrocenylsilane), and POSS (polyoctahedral silsesquioxanes) combined with an organic block not only offer high etch contrast for the fabrication of nanopatterns, but also offer smaller feature sizes due to the high interaction parameter (χ) resulting from the chemical incompatibility between the Si-containing block and the organic block. − Therefore, there has been considerable study directed toward the synthesis and self-assembly of Si-BCPs in bulk and thin films. ,− …”