Local Potential Measurements in Silicon Devices using Atomic Force Microscopy with Conductive Tips

In this paper another application of an Atomic Force Microscope (AFM) using conductive tips is presented: Voltages are applied to the semiconductor structure while a conductive tip is scanned across a cross section of the device. The tip is used as a voltage probe determining the local potential with very high resolution (nm limited by the tip size). Home-made cantilevers have been used to determine both one-and two-dimensional distributions. After a description of the preparation method the promising properties of the technique are demonstrated for simple p-n junctions. Prospectives for charge carrier profiling and electrical characterisation of fully processed devices are discussed.