Sharpening of conductive nanoprobes for scanning tunneling microscopy by field-directed sputter sharpening

This thesis presents a novel sputter erosion sharpening technique for the production of conductive probes on nanometer and atomic scales. This field-directed sputter sharpening procedure is shown to reliably sharpen both tungsten and platinum-iridium alloy probes and to produce atomic-scale topological changes, distinct from traditional sputter erosion sharpening. Possible justification for this effect is presented in the form of controlled ion current modulation at the probe apex. Furthermore, the probes are found to facilitate high-fidelity patterning of the hydrogen passivated silicon surface.unpublishednot peer reviewe