Single electron tunneling force microscopy

The development and first application of a new scanning probe microscopy technique is described. This technique, called single-electron tunneling force microscopy (SETFM), is used to image and to perform spectroscopy of individual localized electronic states in completely nonconducting oxide surfaces. The SETFM detects single-electron tunneling events between a metallized atomic force microscope probe and individual electronic states by electrostatic force measurements. The experimental arrangement is described, with accompanying physical models to explain tunneling detection by electrostatic force. Spectroscopic measurements are performed on an individual electronic defect in a silicon dioxide film. An electrostatic model is developed to interpret the spectroscopic measurements. The measurements reveal the state energy at 5.5+/-0.2 eV below the silicon dioxide conduction band edge. Spectroscopic measurements show evidence for energy relaxation of the electronic state. Random telegraph signals are also observed in these measurements. A model for the random telegraph signals is presented. The SETFM method to acquire images with ∼1 nanometer spatial resolution of localized states in a completely nonconducting surface is described. Single-electron tunneling images of silicon dioxide are presented and interpreted. The images reveal information about the spatial distribution and density of electronic defects.