SC-CO2 ANNEALING OF BLOCK COPOLYMER THIN FILMS

ANABELLA A. ABATE; GIANG T. VU; CRISTIAN M. PIQUERAS; FRIEDERIKE SCHMID; DANIEL A. VEGA

Ciudad Autonoma de Buenos Aires

Simposio; SIMPOSIO INTERNACIONAL: FRONTIERS IN PHYSICAL SCIENCES; 2016

International Center for Advanced Studies (ICAS) de la Universidad Nacional de San Martín (UNSAM)

One of the main drawbacks of using self-assembly in nanofabrication technologies is the lack of regularity due to the presence of a rich variety of topological defects like domain walls, disclinations, and dislocations. Up to now, significant effort has been dedicated to controlling order in quasi-two-dimensional block copolymer thin film. However, the ability of block copolymers to self- assemble into a diversity of three-dimensional (3D) structures with different symmetries suggests that it should be possible to use these systems to obtain templates for 3D nanofabrication.Here we explore the use of supercritical (sc) carbon dioxide as an environmentally friendly solvent for controlling the self-assembly of block copolymer thin films. The high diffusivity and solubility of sc-CO2 in the block copolymer system depress its glass transition temperature, dilutes the network of topological entanglements and thus, enhances polymer chain mobility. In addition, the sc-CO2 reduces the preferential interaction between the substrate and one of the blocks and thus favors the appearance of arrays of hexagonally packed cylinders, perpendicularly arranged with regards to the substrate.