Fig. 3
From: Directed self-assembly of a two-state block copolymer system
SEM images of square confinement with openings and the resulting block copolymer patterns. Ratio of 0 state (denoted by p0) for each type was measured in a large array. Binary states were determined based on the number of horizontal and vertical openings. a, f Square confinement with one horizontal opening. Preferential horizontal alignment (0 state) was observed. b, g Square confinement with two horizontal openings on non-adjacent sides. Stronger preferential horizontal alignment was observed. c, h Square confinement with two openings on adjacent sides. Alignment in both directions was observed with equal probability. d, i Square confinement with three openings. Preferential horizontal alignment was observed. e, j Square confinement with four openings. Alignment in both directions was observed with equal probability. These results demonstrate the templating effect from openings. Scale bars, 200Â nm