Three-dimensional superlattice engineering with block copolymer epitaxy
Three-dimensional (3-D) structures at the nanoscale are important in modern devices, although their fabrication with traditional top-down approaches is complex and expensive. Block copolymers (BCPs) that are analogous to atomic lattices can spontaneously form a rich variety of 3-D nanostructures to substantially simplify 3-D nanofabrication. In a new report on Science Advances, Jiaxing Ren and a research team in molecular engineering, chemical engineering and materials science at the University of Chicago, Technion-Israel Institute of Technology and the Argonne National Laboratory in the U.S. and Israel formed a 3-D superlattice using BCP micelles. They controlled the process using lithographically defined 2-D templates that matched a crystallographic plane in the 3-D superlattice. Using scanning transmission electron microscopy tomography, the team demonstrated precise control across the lattice symmetry and orientation. They achieved excellent ordering and substrate registration through 284-nanometer-thick films. To mediate lattice stability, the scientists tapped into molecular packing frustration of the...