Intermittent Bias Application in Kelvin Probe Force Microscopy for Accurate Determination of Surface Potential

Abstract

We propose an intermittent bias application method in Kelvin probe force microscopy (KFM) to suppress electrostatic force variation due to an oscillatory motion of a KFM tip. In this method, spiky biases, instead of the bias in a sinusoidal waveform, which is used in conventional KFM, are intermittently applied to generate electrostatic force at exact moments when the tip approaches the closest position to a sample surface. The observed potential distribution around self-assembled InAs quantum dots indicates that the intermittent bias application method improved the quality of the potential images and that the achieved spatial resolution was estimated to be better than 10 nm.