Electrostatic actuator probe with curved electrodes for time-of-flight scanning force microscopy

In this study, we fabricated an electrostatic actuator probe having curved electrodes and evaluated its applicability for use in time-of-flight scanning force microscopy. In this probe, the end position of a cantilever with a tip is switched through electrostatic pull-in effect; the measurement modes can be changed between mass analysis and scanning force microscopy (SFM) modes. We achieved a large displacement of 400 μm for changing working modes. To prevent electrical shortage of the probe and curved electrodes, stoppers were formed along the curved electrodes. Because of the pull-in effect, the spring constant and resonance frequency increased through stiction of the cantilever to the stoppers. Using the fabricated probe, the SFM imaging of a sample featuring a 2-μm -pitch Au grid was demonstrated.