Automatic kelvin probe compatible with ultrahigh vacuum

This article describes a new type of in situ ultrahigh-vacuum compatible kelvin probe based on a voice-coil driving mechanism. This design exhibits several advantages over conventional mechanical feed-through and (in situ) piezoelectric devices in regard to the possibility of multiple probe geometry, flexibility of probe geometry, amplitude of oscillation, and pure paranel vibration. Automatic setup and constant spacing features are achieved using a digital-to-analog converter (DA C) steered offset potential. The combination of very low driver noise pick -up and data-acquisition system (DAS) signal processing techniques results in a work function (wf) resolution, under optimal conditions, of < 0.1 meY. Due to its high surface sensitivity and compatibility with standard sample cleaning and analysis techniques this design has numerous applications in surface studies, e.g., adsorption kinetics, sample topography and homogeneity, sputter profiles, etc. For semiconductor specimens the high wi resolution makes it eminently suitable for surface photovoltage (SPV) spectroscopy.