Scanning probe characterization of surfaces

An apparatus for characterizing electrical properties of a dielectric surface, to detect locations on a dielectric surface where electron tunneling may occur, the apparatus comprising:

• an atomic force probe;
• a mechanical actuator coupled to the atomic force probe;
• a mechanical modulator coupled to the mechanical actuator, the mechanical modulator configured to modulate the mechanical actuator and the atomic force probe at the resonant frequency of the atomic force probe;
• an electrical modulator coupled to the atomic force probe;
• a feedback sensing circuit coupled to the mechanical modulator, the feedback circuit configured to detect movement of the atomic force probe and to provide information about the movement of the atomic force probe to the mechanical modulator to allow the mechanical modulator to modulate the mechanical actuator and the atomic force probe at the resonant frequency of the atomic force probe as the resonant frequency of the atomic force probe changes;
• and
• an FM detector coupled to the feedback sensing circuit and configured to detect changes in the resonant frequency of the atomic force probe.

A method of characterizing a dielectric surface by detecting electric surface potential of the surface, the method comprising acts of:

• positioning an atomic force probe near the dielectric surface;
• mechanically oscillating an atomic force probe at a resonant frequency of the force probe;
• electrically modulating the atomic force probe at an electrical modulation frequency;
• and
• measuring an FM modulation of the resonant frequency of the atomic force probe due to the surface potential of the dielectric surface the FM modulation of the resonant frequency of the atomic force probe being at the electrical modulation frequency.