Etch-stop method for reliably fabricating sharp yet mechanically stable scanning tunneling microscope tips

TL;DR

This paper introduces an improved electrochemical etching method for tungsten STM tips using an etch stop to achieve sharp, stable tips with minimal skill required, enhancing reproducibility and reliability.

Contribution

It presents a novel etch-stop technique that simplifies and optimizes the fabrication of sharp, mechanically stable STM tips compared to previous methods.

Findings

Tips have consistent sharpness and stability

Reduced skill requirement for tip fabrication

Enhanced reproducibility of tip quality

Abstract

An extension of the direct-current, double-lamella drop-off technique for electrochemically etching tungsten scanning-tunneling-microscope tips is presented. The key fabrication step introduced here is the use of an etch stop as a simple but accurate way to optimize the contact area between the etchant and the wire. By restricting the etching process, the final cone angle of the tips can be made sharp and mechanically stable without a lot of finesse from the STM tip maker.