Controlled surface damage using a scanning tunnelling microscope on platinum and platinum-carbon films and the in-situ correction of tip defects

Abstract

The use of a scanning tunnelling microscope to alter surface morphology from the nanometer to the atomic scale has been described for a number of materials. Here a technique for the creation of stable features on platinum and platinum-carbon films is demonstrated. This is achieved by applying tunnelling biases exceeding ±2.9-3.1 V and ±3.2-3.4 V for the platinum and platinum-carbon films, respectively. Moving a tip which is highly biased generally results in trenches being created in the surface, although, in the case of the platinum-carbon films, material may also be deposited. These effects are ascribed to an electrostatic interaction between the tip and the surface. We also identify the presence of positive and negative contrast artefacts on a platinum film and discuss the possible application of this work to studies of biomolecules. In addition, we demonstrate the correction of a tip defect in-situ through the application of high-voltage biases.