Charging and discharging behavior in dielectric-coated MEMS electrodes probed by Kelvin probe force microscopy

• Published in: Journal of micromechanics and microengineering Vol. 22; no. 6; pp. 65031 - 9
• Main Authors: Laboriante, Ian, Farrokhzad, Nassim, Fisch, Maxwell, Shavezipur, Mohammad, Carraro, Carlo, Maboudian, Roya, Bai, Qing, Liu, Maozi, Hoen, Storrs
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.06.2012; Institute of Physics
• Subjects: Charging; Coatings; dielectric charging; Dielectrics; Discharge; Electrodes; Exact sciences and technology; finite element simulations; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Kelvin probe force microscopy; Mechanical instruments, equipment and techniques; MEMS; metal-insulator interface; Micromechanical devices and systems; Microscopy; Monolayers; Physics; self-assembled monolayer; surface potential; surface vibrational spectroscopy; Surface water; Dielectric materials; Bias; Aluminium nitride; Silicon nitride; Mobility; Kelvin probe; Electrode material; Ceramic coating; Surface metrology; Dielectric coating; Discharge charge cycle; Electrodes; Finite element method; Silicon oxides; Force microscopy; Modelling; Microelectromechanical device; Surface potential; Electrostatic force
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/22/6/065031

The charging and discharging behavior of silicon dioxide, silicon nitride and aluminum nitride dielectric coatings on microfabricated aluminum electrodes in response to an applied voltage, thermal treatment, operating environment and monolayer coating have been investigated through Kelvin probe force microscopy (KPFM) techniques. Correlated results from surface potential measurements and finite element simulations demonstrate the existence of capacitive coupling between the KPFM probe tip assembly and the device sample which give rise to as much as 20-40% difference between the applied bias and the measured surface potential. Surface charge mobility on the three material systems has been differentiated focusing on the influence of bulk and surface water and the relevant physicochemical properties. The merits and limitations of proposed schemes for mitigating the effects of dielectric charging, including thermal treatment and monolayer coating, are presented.