Quantitative scanning capacitance spectroscopy

Abstract

In this work, a setup for quantitative scanning capacitance spectroscopy is introduced, where an ultrahigh precision, calibrated capacitance bridge is used together with a commercially available atomic force microscope (AFM). We show that capacitance data measured with this setup are of comparable quality as data obtained on macroscopic metal oxide semiconductor capacitors. In addition, our setup is sensitive enough to resolve the energy distribution of interface traps with the spatial resolution of an AFM. This is an advantage compared to conventional scanning capacitance microscopes, which have a limited energy resolution and only yield qualitative results due to large modulation voltages.