Ion beam sputtering method for progressive reduction of nanostructures dimensions

TL;DR

This paper introduces an ion beam sputtering technique for precisely reducing the dimensions of nanostructures like nanowires and SETs, enabling controlled size reduction without damaging the structures.

Contribution

The study presents a novel ion beam sputtering method for progressive, repeatable reduction of nanostructure dimensions, demonstrated on aluminum nanowires and SETs.

Findings

Effective reduction of nanowire diameter from ~65 nm to ~30 nm.

40% reduction in SET tunnel junction area.

Method allows multiple sputtering sessions without damaging samples.

Abstract

An ion beam based dry etching method has been developed for progressive reduction of dimensions of prefabricated nanostructures. The method has been successfully applied to aluminum nanowires and aluminum single electron transistors (SET). The method is based on removal of material from the structures when exposed to energetic argon ions and it was shown to be applicable multiple times to the same sample. The electrical measurements and samples imaging in between the sputtering sessions clearly indicated that the dimensions, i.e. cross-section of the nanowires and area of the tunnel junctions in SET, were progressively reduced without noticeable degradation of the sample structure. We were able to reduce the effective diameter of aluminum nanowires from ~65 nm down to ~30 nm, whereas the tunnel junction area has been reduced by 40 %.