Atomic scale trap state characterization by dynamic tunneling force microscopy

Dynamic tunneling force microscopy (DTFM) is applied to the study of point defects in an inter-layer dielectric film. A recent development enables simultaneous acquisition of DTFM, surface potential, and topographic images while under active height feedback control. The images show no clear correlation between trap state location and surface potential or topography of the surface. The energy and depth of individual trap states are determined by DTFM images obtained at different probe tip heights and applied voltages and quantitative tunneling and electrostatic models. The measured density of states in these films is found to be approximately 11019cm3eV1 near the dielectric film surface.