IMPROVEMENT OF KELVIN PROBE FORCE MICROSCOPE (KFM) SYSTEM

The Kelvin probe force microscope (KFM) is a useful tool that measures the surface potentials of both conducting and nonconducting materials. Recently, we have succeeded in improving the accuracy of potential measurements and increased the lateral resolution of the topographic image. Furthermore, Z axis servo control was improved to prevent the tip from coming into contact with the sample surface during scanning. Finally, the force gradient between the tip and the sample became steeper during the acquisition of the topographic image due to the inactivation of the modulation AC voltage. As a result, the potential resolution was less than 1 mV and the lateral resolution of the topographic image was improved to as high as 10 nm.