Sub-25 nm Inorganic and Dielectric Nanopattern Arrays on Substrates: A Block Copolymer-Assisted Lithography.

A range of well-ordered inorganic (antimony, tin, and tungsten oxide) and dielectric (silica, alumina, and hafnia) nanoparticles and nanowire array patterns are created on substrates by a low-cost block copolymer (BCP) approach. A cylindrical-phase PS- b -PEO BCP is used as a template with hexagonally ordered perpendicular or parallel orientation of PEO cylinders. The solvent annealing parameters such as solvents, temperature, time, and so forth are optimized to achieve the desired patterns. An established BCP in situ inclusion protocol is utilized to achieve the material nanopatterns by spin coating the respective precursor ethanolic solution on the template followed by UV/ozone treatment for oxide conversion and polymer removal. Furthermore, the precursor solution concentrations and stirring times are calibrated to achieve isolated, well-ordered, and uniform-diameter and -thickness nanoparticles and nanowires. All of the material nanopatterns are mimicking the parent BCP nanopatterns. The phases of all of the nanopatterns are determined by X-ray photoelectron spectroscopy. The inorganic and dielectric nanopattern arrays are patterned on a graphoepitaxial substrate for device application.