title: Sub-10 nm Silicon Nanopillar Fabrication Using Fast and Brushless Thermal Assembly of PS-b-PDMS Diblock Copolymer.
abstract: A new approach to obtaining spherical nanodomains using polystyrene-block-polydimethylsiloxane (PS-b-PDMS) is proposed. To reduce drastically the process time, we blended a copolymer with cylindrical morphology with a PS homopolymer. Adding PS homopolymer into a low-molar-mass cylindrical morphology PS-b-PDMS system drives it toward a spherical morphology. Besides, by controlling the as-spun state, spherical PDMS nanodomains could be kept and thermally arranged. This PS-homopolymer addition allows not only an efficient, purely thermal arrangement process of spheres but also the ability to work directly on nontreated silicon substrates. Indeed, as shown by STEM measurements, no PS brush surface treatment was necessary in our study to avoid a PDMS wetting layer at the interface with the Si substrate. Our approach was compared to a sphere-forming diblock copolymer, which needs a longer thermal annealing. Furthermore, GISAXS measurements provided complete information on PDMS sphere features. Excellent long-range order spherical microdomains were therefore produced on flat surfaces and inside graphoepitaxy trenches with a period of 21 nm, as were in-plane spheres with a diameter of 8 nm with a 15 min thermal annealing. Finally, direct plasma-etching transfer into the silicon substrate was demonstrated, and 20 nm high silicon nanopillars were obtained, which are very promising results for various nanopatterning applications.
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Garnier
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Javier
authors.initials: J
authors.lastname: Arias-Zapata
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-SP2M , F-38000 Grenoble, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Marconot
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Arnaud
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Böhme
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Girardot
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-SP2M , F-38000 Grenoble, France.|IUT-1 , 17 quai C. Bernard, F-38000 Grenoble, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Buttard
authors.affiliation: Université Grenoble Alpes , F-38000 Grenoble, France.|CNRS, LTM , F-38000 Grenoble, France.|CEA, LETI , MINATEC Campus, F-38054 Grenoble, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Zelsmann
keywords: BCPs; DSA; PS-b-PDMS; block copolymers; directed self-assembly; plasma etching; polystyrene homopolymer; polystyrene-block-polydimethylsiloxane; silicon nanostructures; spherical morphology; thermal annealing