Surface patterning with carbon thin films by nanosphere lithography

Nanosphere lithography was used to fabricate surface patterns on glass substrate. Polystyrene (PS) colloidal microspheres were first fabricated into an ordered monolayer/multilayers on the substrate via self-assembly process using a flow-controlled vertical deposition (FCVD) method. A carbon precursor, namely, sucrose solution, was infiltrated into the voids between the spheres. Carbonization of sucrose ended up with the formation of glassy carbons. Removal of the colloidal spheres left behind a surface pattern of thin carbon film. Depending on the template structures, the carbon patterns can be quadrangular or hexagonal in shape. A further step was taken to use the patterns as a template to grow silica spheres with a nonclose-packed structure.