title: Enhanced Lateral Ordering in Cylinder Forming PS-b-PMMA Block Copolymers Exploiting the Entrapped Solvent.
abstract: The self-assembly of block copolymer (BCP) thin films produces dense and ordered nanostructures. Their exploitation as templates for nanolithography requires the capability to control the lateral order of the nanodomains. Among a multiplicity of polymers, the widely studied all-organic polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) BCP can easily form nanodomains perpendicularly oriented with respect to the substrate, since the weakly unbalanced surface interactions are effectively neutralized by grafting to the substrate an appropriate poly(styrene-random-methyl methacrylate) P(S-r-MMA) random copolymer (RCP). This benefit along with the selective etching of the PMMA component and the chemical similarity with the standard photoresist materials deserved for PS-b-PMMA the role of BCP of choice for the technological implementation in nanolithography. This work demonstrates that the synergic effect of thermal annealing with the initial solvent naturally trapped in the basic RCP + BCP system after the deposition process can be exploited to enhance the lateral order. The solvent content embedded in the total RCP + BCP system can be tuned by changing the molecular weight and thus the thickness of the grafted RCP brush layer, without introducing external reservoirs or dedicated setup and/or systems. The appropriate supply of solvent supports a grain coarsening kinetics following a power law with a 1/3 growth exponent for standing hexagonally ordered cylinders.
authors.affiliation: Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Seguini
authors.affiliation: Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Zanenga
authors.affiliation: Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, Italy.|Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ''A. Avogadro'', INSTM , UdR Alessandria, Viale T. Michel 11, I-15121 Alessandria, Italy.
authors.forename: Tommaso J
authors.initials: TJ
authors.lastname: Giammaria
authors.affiliation: Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, Italy.|Università degli Studi di Milano , Via Celoria 16, I-20133 Milano, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Ceresoli
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ''A. Avogadro'', INSTM , UdR Alessandria, Viale T. Michel 11, I-15121 Alessandria, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Sparnacci
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ''A. Avogadro'', INSTM , UdR Alessandria, Viale T. Michel 11, I-15121 Alessandria, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Antonioli
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ''A. Avogadro'', INSTM , UdR Alessandria, Viale T. Michel 11, I-15121 Alessandria, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Gianotti
authors.affiliation: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università del Piemonte Orientale ''A. Avogadro'', INSTM , UdR Alessandria, Viale T. Michel 11, I-15121 Alessandria, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Laus
authors.affiliation: Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Perego
keywords: PS-b-PMMA; block copolymers (BCP); correlation length; grain coarsening; random copolymers (RCP); rapid thermal processing (RTP); solvent