(382f) Controlled Long Range Orientation of Block Copolymer Nanostructures Through Soft Confinement Solvent Vapor Annealing

Long range alignment of block copolymer domains in thin films is generally obtained through relatively complex processing involving pre-patterned substrates,¹ electric fields,² crystal faults,³ or slow thermal zone annealing.⁴ In this work, we describe a simple method that is similar to typical solvent vapor annealing (SVA) strategies except that the surface of the block copolymer film is capped with a swellable elastomer.  By controlling the shape and size of the elastomer on the block copolymer film during SVA, the orientation of perpendicular lamellae can be controlled over 180 degrees.  We will discuss how the thickness of the film, block copolymer composition, and solvent using in SVA impact the alignment and orientation of block copolymer domains.  From GISAXS, the Herman’s orientation parameter of the films can exceed 0.95 (second order parameter) under typical SVA conditions for less than 2 h.    

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