Lithographically induced self-assembly of periodic polymer micropillar arrays

We observed, and believe it to be the first time, the self-formation of periodic, supramolecular (micrometer scale) pillar arrays in a thin, single-homopolymer film melt, which was originally flat on a plate. The self-formation was induced by placing a second plate (called a mask) a distance above the polymer film. The pillars, formed by rising against the gravitational force and surface tension, bridge the two plates. The pillar height is equal to the plate-mask separation, which is two to seven times the film's initial thickness. If the surface of the mask has a protruding pattern (e.g., a triangle or rectangle), the pillar array can be formed only under the protruding pattern with the edge of the array aligned to the boundary of the mask pattern. We also discuss a model and novel applications of lithographically induced self-assembly. (C) 1999 American Vacuum Society. [S0734-211X(99)15206-5].