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

Tandra Ghoshal,Michael A Morris,Nadezda Prochukhan

doi:10.1021/acsomega.1c05124

Abstract

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.

Highlights

Large-scale arrays of nanostructures on substrates are used in many applications, including photonic,[1] electronic,[2] sensor,[3] optoelectronic,[4] microreactor,[5] piezoelectric,[6] porous filtration membrane,[7] energy conversion,[8] and energy storage devices.[9]
The self-assembled di-Block copolymer (BCP) film can be used as an on-chip etch mask or a template, and material patterns can be produced by selective removal of one copolymer block and/or selective inclusion of chemical components to a chosen block with subsequent processing.[14,15]
We have extended the idea of the formation of material nanopatterns for other inorganic oxide semiconductors and dielectrics

Summary

■ INTRODUCTION

Large-scale arrays of nanostructures on substrates are used in many applications, including photonic,[1] electronic,[2] sensor,[3] optoelectronic,[4] microreactor,[5] piezoelectric,[6] porous filtration membrane,[7] energy conversion,[8] and energy storage devices.[9]. The self-assembled di-BCP film can be used as an on-chip etch mask or a template, and material patterns can be produced by selective removal of one copolymer block and/or selective inclusion of chemical components to a chosen block with subsequent processing.[14,15] there is significant additional potential for the oxides as they covered almost all aspects of material science and physics in areas including properties like superconductivity, ferroelectricity, magnetism, and more This is due to their two unique characteristics: variation in valence states and oxygen vacancies.[16] We have reported the formation of inorganic. Spectroscopic and microscopic techniques reveal the formation of uniform sized arrays of oxide semiconductors and dielectrics of nanoparticles and nanowires

■ RESULTS AND DISCUSSION

■ CONCLUSIONS

■ REFERENCES