MONOLAYER FILMS OF DIBLOCK COPOLYMER MICRODOMAINS FOR NANOLITHOGRAPHIC APPLICATIONS

Several techniques have been investigated for creating large-area thin films of diblock copolymers, with well-ordered two-dimensional period ic microstructure on the scale of a few tens of nanometres. Such struc tures might potentially be used as templates for lithography, at a len gth scale not easily accessed by electron-beam methods. Using a copoly mer with a spherical microdomain structure, we find that it is quite e asy to obtain large-area films consisting of a monolayer of spherical domains, arranged on a hexagonal lattice with a lattice constant of 33 nm. Copolymers with cylindrical microstructure typically orient paral lel to the substrate and free surface, it has been found that the perp endicular orientation is metastable: if a well- or poorly-ordered film is initially prepared with the cylinders perpendicular to the surface , annealing results in a well-ordered film with the same orientation, with a lattice constant of 27 nm for the polymer used in this study. F or both cylinders and spheres, grains measuring typically 30 x 30 latt ice constants are readily obtained.