Frequency dependent capacitance spectroscopy using conductive diamond tips on GaAs/Al2O3 junctions

Abstract

In this work, an unusual low frequency behavior observed in scanning capacitance microscopy/spectroscopy on GaAs/Al2O3 junctions is investigated. Using a two-dimensional simulation, we show that the frequency behavior of the capacitance—voltage curves can be explained through an increased minority carrier concentration at to the GaAs–Al2O3 interface and tip geometry effects on the nanoscale. An analytic approach to estimate the transition frequency between the low frequency and high frequency regime is also given.

Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy

“…For example, conductive atomic force microscopy (CAFM) enables us to investigate the conductive properties of individual quantum structures [19-21], while scanning Kelvin microscopy (SKM) [22] and scanning capacitance microscopy (SCM) [23] are valuable tools for measuring the surface potential and carrier density distributions of individual quantum structures. These techniques have already been performed to study the electrical properties of individual quantum dots [24-31], but the electrical property studies on individual QRs are still lacking.…”