MEMS Ring Resonators for Laserless AFM With Sub-nanoNewton Force Resolution

• Published in: Journal of microelectromechanical systems Vol. 21; no. 2; pp. 385 - 397
• Main Authors: Algre, E., Zhuang Xiong, Faucher, M., Walter, B., Buchaillot, L., Legrand, B.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2012; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Atomic force microscopy (AFM); electromechanical microresonators; Engineering Sciences; Exact sciences and technology; Force; force probes; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Optical ring resonators; Physics; Precision engineering, watch making; Probes; Resonant frequency; Sensors; Transducers; Vibrations; Near field; Atomic force microscopy; Atomic force microscopy (AFM); Force measurement; Capacitive transducer; Precision engineering; Measurement sensor; Force field; Nanotip; electromechanical microresonators; force probes; Experimental study; Intermittency; Vibrations; Nanometer scale; Ring resonator; Resonance frequency; Displacement measurement; Silicon; Electronic circuits; Microelectromechanical device; Transducers; Force; Resonant frequency; Sensors; Probes; Optical ring resonators
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2011.2179012

A concept of atomic force microscopy (AFM) oscillating sensors using electromechanical silicon microresonators is presented, and imaging capabilities are demonstrated. The microresonators are designed to feature MHz resonance frequencies, and they are batch fabricated using standard silicon microtechnologies. Integrated capacitive transducers allow to drive the resonator and to sense its vibration amplitude. A nanotip is located at a maximum of displacement for sensing near-field forces when interacting with a surface. The device has been mounted on a commercial AFM setup through a dedicated probe holder and a preprocessing electronic circuit. Experiments show that intermittent contact AFM is possible with a tip vibration amplitude of a few nanometers. AFM images have been acquired on silicon micro and nanopatterns. A force resolution of 0.2 nN/√Hz is deduced from the measurements.