STM-induced surface aggregates on metals and oxidized silicon

TL;DR

This study investigates how scanning tunneling microscopy (STM) induces surface aggregation of carbon-based materials on platinum and oxidized silicon, revealing the process's dependence on measurement parameters and resulting film thicknesses.

Contribution

It demonstrates that STM measurements can cause surface aggregation of carbon materials, with the extent influenced by scan number and voltage, providing insights into surface modification processes.

Findings

Aggregation increases with number of scans

Higher tunneling voltage leads to more aggregation

Film thicknesses up to 10 nm observed after multiple scans

Abstract

We have observed an aggregation of carbon or carbon derivatives on platinum and natively oxidized silicon surfaces during STM measurements in ultra-high vacuum on solvent-cleaned samples previously structured by e-beam lithography. We have imaged the aggregated layer with scanning tunneling microscopy (STM) as well as scanning electron microscopy (SEM). The amount of the aggregated material increases with the number of STM scans and with the tunneling voltage. Film thicknesses of up to 10 nm with five successive STM measurements have been obtained.