Conception and fabrication of piezo-resistive ring-shaped AFM probes

A new concept of Atomic Force Microscope (AFM) oscillating probes using electrostatic excitation and piezoresistive detection is presented. The probe is characterized by electrical methods in vacuum chamber and by mechanical methods in air. The frequency-mixing measurement technique is developed to reduce the parasitic signal level. These probes resonance frequencies are in the 1MHz range and the quality factor is measured about 53,000 in vacuum and 3,000 in air. The force resolution deduced from the measurements is about 8 pN/Hz^0.5.