Near Atomic Spatial Resolution Electrical Characterization

The proposal “Down to Atomic Resolution Kelvin Probing of Integrated Circuits (DARK-PICs)” deals with improvement of Kelvin Force Microscopy (KFM) allowing detection/mapping of surface potential and related electric properties of semiconductors and integrated circuits at the atomic scale. This Phase I deals with the feasibility of developing a commercially KFM system with a spatial resolution (~1 nm) and ~1 mV of potential sensitivity. A novel low-noise electronic controller will be used for simultaneous collection the probe responses at multiple frequencies and extraction of surface potential and capacitance gradients. A thorough study of the reference, calibration and test samples will be performed to prove the nanometer-scale studies of surface work functions, structures with different doping type and levels, interfaces of metals with semiconductors and insulators, and nanoscale devices. A non-destructive characterization will be enforced by applying small oscillatory amplitudes (ô€€€1 nm) of AFM probes with small spring constants (<1 N/m) and minimal AC/DC electric perturbations (1-2 Volts). Tuning fork probes will be tested to avoid optical excitation of photo-sensitive samples. The successful development of such a system will allow direct, non-destructive characterization of semiconductor doping processes, measurement of surface potentials, the examination of interfaces, and detection and identification of defects IC.