NSF-DFG: Advances in Ion-Surface Interaction-Driven Manufacturing of One-Dimensional Metal Oxide Heterostructures

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

This grant supports research into the manufacture of large area arrays of nanostructures needed in many application areas such as biomedical sensing and quantum technologies. The research benefits the advancement of science associated with the formation of nanostructures through ion beam surface interactions. In this manufacturing process, the combined atom and ionized particle impingement at the surface under oblique angle of incidence is used to controllably form arrays of three-dimensional nanostructures. A wide spectrum of materials and elemental combinations can be used in this manufacturing process leading to a versatility in nanostructure formation. This process would provide a measure of control over the physical and chemical structure which currently limits the range of resulting elemental compositions, nanostructure geometries and shapes. The use of multiple of ion beams combined with selected elemental compositions and choice of kinetic properties widely extends the range of materials for nanostructure manufacturing. This research closes a gap in three-dimensional nanomaterials fabrication to achieve precise geometrical shape and elemental control. The new nanomaterials with improved shape and material composition control and precision will enable new applications, for example in photonics, energy harvesting, or biosensing. This research will benefit the economy and society of the United States through enabling new materials for device applications. The grant supports an international collaborative study utilizing and addressing manufacturing, plasma physics, materials science, and numerical methods. A strategic alignment with German collaborators under a joint program co-funded by both the National Science Foundation and the German National Science Foundation accelerates the progress and research outcomes. International exchange and interdisciplinary approaches support engineering workforce training and serves to broaden participation of underrepresented groups in science and education. Glancing angle deposition is a versatile bottom-up technique to create three-dimensional nanostructures without the inclusion of expensive and time-consuming lithographic and etching processes. This work addresses current limitations for broad area nanostructure formation and subsequent technical use which result from structure fanning, which is the broadening of structure thickness or diameter with increasing height, lack of controlled structure arrangements across a substrate surface and insufficient control over compound compositions for relevant oxides, nitrides, and carbides. Ion processing overcomes these barriers by utilizing ion erosion for the initial substrate patterning, reactive ion-assisted growth for compound formation with precise stoichiometry and ion beam figuring to limit fanning and improve structure homogeneity. The research will investigate mechanisms which determine the influence of low-energy ion processing during glancing angle deposition using a computationally driven experimental approach. The research team will perform experiments for ion-assisted manufacturing and material modification supported by Monte Carlo based simulations to explore ion-surface driven interactions on the nanoscale. The experiments are characterized by in situ optical process control and finite element based dynamic modeling to explore the impact of ions during material fabrication in real time. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.