A novel SPM probe with MOS transistor and nano tip for bio application

In this paper, the novel SPM (Scanning Probe Microscope) probe is designed and fabricated for the measurement of the surface electric properties of the bio materials. The probe has two parts, the planar MOS (Metal-Oxide-Semiconductor) transistor which is sensitive to the electric signal and the FIB (Focused Ion Beam) nano tip. Since MOS transistor lias high working frequency and high sensitivity, and the FIB nano tip has nanometer scale tip radius, the probe can rapidly detect small localized electric properties with high sensitivity and high resolution. The MOS transistor is fabricated with the common semiconductor process, and the nano tip is grown by the FIB system. The planar structure of the MOS transistor makes the fabrication process easier, which is the advantage on the commercial production. Various electric signals are applied using the function generator, and the measured data shows the promising aspect of the electric property detection of the bio materials with high sensitivity and high resolution.