Wafer-scale colloidal lithography based on self-assembly of polystyrene nanospheres and atomic layer deposition

This paper reports a facile and robust wafer-scale colloidal lithography using polystyrene nanospheres. This technique is based on a combination of two simple and scalable processes: the self-assembly of polystyrene nanospheres by spin coating and the atomic layer deposition. Patterns, such as two dimensional hole-arrays, can be routinely fabricated over 4 inch diameter wafers owing to high reproducibility of this novel method. The hole size and pitch can be controlled by heat treatment and the use of polystyrene nanospheres with different diameters, respectively. We demonstrate five- to ten-fold enhancement in the photoluminescence of phosphor films by constructing two dimensional SiN_x photonic crystals on the films using this technique. It is expected that atomic layer deposition assisted polystyrene colloidal lithography would be incorporated easily in the mass fabrication of optoelectronic devices, such as light emitting diodes.