A single electron tunneling force spectroscopy (SETFS) system (10) can perform a series of surface potential charge measurements at an array of voltages (V) and tip-sample heights (Z). These measurements are combined with a tunneling model that includes the dependence of the tunneling probability on trap state depth and energy. Simultaneous measurement of the depth and energy of individual trap states in a sample, such as a dielectric film, with an atomic scale of spatial resolution can be achieved. When combined with two-dimensional trap state imaging, such techniques provide for three-dimensional imaging of electronic defect states with atomic scale spatial resolution.