Nanoscale mapping of thermal and mechanical properties of bare and metal-covered self-assembled block copolymer thin films
Sachat, Alexandros el (Institut Català de Nanociència i Nanotecnologia)
Spièce, Jean (Lancaster University. Physics Department)
Evangeli, Charalambos (Lancaster University. Physics Department)
Robson, Alexander James (Lancaster University. Physics Department)
Kreuzer, Martin (Institut Català de Nanociència i Nanotecnologia)
Rodríguez Laguna, María del Rocío (Institut Català de Nanociència i Nanotecnologia)
Chávez Ángel, Emigdio (Institut Català de Nanociència i Nanotecnologia)
Sledzinska, Marianna (Institut Català de Nanociència i Nanotecnologia)
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)
Kolosov, Oleg Victor (Lancaster University. Physics Department)
Alzina, Francesc (Institut Català de Nanociència i Nanotecnologia)

Date:	2020
Abstract:	We report on the structural, mechanical, and thermal analysis of 40 nm thick polystyrene-block-poly(ethylene oxide) (PS-b-PEO) block copolymer (BCP) films coated with evaporated chromium layers of different thicknesses (1, 2, and 5 nm). Solvent annealing processes allow the structural control of the BCP films morphology by rearranging the position of the PEO cylinders parallel to the substrate plane. High-vacuum scanning thermal microscopy and ultrasonic force microscopy measurements performed in ambient pressure revealed that coated ultrathin metal layers strongly influence the heat dissipation in the BCP films and the local surface stiffness of the individual BCP domains, respectively. The measured tip-sample effective thermal resistance decreases from 6. 1 × 107 to 2. 5 × 107 K W-1 with increasing Cr film thickness. In addition, scanning probe microscopy measurements allow the thermal and mechanical mapping of the two segregated polymer domains (PEO-PS) of sub-50 nm characteristic sizes, with sub-10 nm thermal spatial resolution. The results revealed the effect of the surface morphology of the BCP and the incorporation of the metal film on the nanoscale thermal properties and volume self-assembly on the mechanical properties. The findings from this study provide insight into the formation of high aspect ratio BCP-metal structures with the more established applications in lithography. In addition, knowledge of the thermal and mechanical properties at the nanoscale is required in emergent applications, where BCPs, or polymers in general, are part of the structure or device. The performance of such devices is commonly related to the requirement of increased heat dissipation while maintaining mechanical flexibility.
Grants:	European Commission 604668 Ministerio de Economía y Competitividad SEV-2017-0706 Ministerio de Economía y Competitividad FIS2015-70862-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-806
Note:	Altres ajuts: the authors acknowledge the financial support from the CERCA Program (Generalitat de Catalunya ).
Rights:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Block copolymers ; Self-assembly ; Thermal and mechanical mapping ; Thermal conductivity ; Scanning probe microscopy
Published in:	ACS Applied Polymer Materials, Vol. 2, issue 2 (Feb. 2020) , p. 487-496, ISSN 2637-6105

DOI: 10.1021/acsapm.9b00924

Preprint 30 p, 705.6 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles