Frequency dependent capacitance spectroscopy using conductive diamond tips on GaAs/[Al.sub.2][O.sub.3] junctions

An unusual low frequency behavior seen in scanning capacitance microscopy/spectroscopy on GaAs/[Al.sub.2][O.sub.3] junctions are examined. A two-dimensional simulation has shown that the frequency behavior of the capacitance-voltage curves is explained by an increased minority carrier concentration at the GaAs-[Al.sub.2][O.sub.3] interface and tip geometry effects on the nanoscale.