Harnessing charge injection in Kelvin probe force microscopy for the evaluation of oxides

Abstract

We report on a quantitative use of Kelvin probe force microscopy (KPFM) for the analysis of charge injection in thin oxides. Here, thin dielectrics are investigated through an atomic force microscopy tip that is used as a movable (virtual) top-electrode. The charge is injected and read-out respectively by alternating the direct contact of the probe with the oxide, and with non-contact surface potential imaging. The contact potential difference (CPD) between the atomic force microscope tip and the oxide surface is used to measure the charge distribution under multiple electrical stress conditions, thus correlating locally trapped charge with dielectric properties.