<i>In situ</i> fabrication and regeneration of microtips for scanning tunnelling microscopy

Abstract

SUMMARY Progress in STM, in particular for the interpretation of the tunnel signals of corrugated surfaces, is related to the possibility of sharpening and regenerating in situ reproducible tips for use as the probe. We proposed two techniques for the production of tips with controlled geometry at the atomic level. These two techniques are based on the production of tips with equilibrium profiles obtained under heat treatments in vacuum and in the presence of an electric field. Based on the pseudo‐stationary profile principle, the microtips can be sharpened in situ and in a reproducible manner, either from initial cylindrical (111)‐W wire, or from breakdown tips; in both cases without the need for heavy control devices (like FIM for example).