On the Impact of Relative Humidity and Environment Gases on Dielectric Charging Process in Capacitive RF MEMS Switches Based on Kelvin Probe Force Microscopy

Heiba Zaghloul (1) , Bharat Bhushan (2) , Patrick Pons (1) , George Papaioannou (3) , Fabio Coccetti (1) , Robert Plana (1)

1 LAAS-MINC - Équipe MIcro et Nanosystèmes pour les Communications sans fil
2 Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics
3 DI NKUA - Department of Informatics and Telecomunications [Kapodistrian Univ]

Dielectric charging is among the major reliability issues that have prevented the commercialization of RF-MEMS Capacitive switches in spite of the extensive study performed on the topic. Moreover, a little work has been performed to study the effect of the relative humidity (RH) and environment gases on the dielectric charging process. In this work we present the effect of RH and the environment gases on the charging/discharging processes in PECVD silicon nitride films based on Kelvin Probe Force Microscopy (KPFM) methodology. The measurements have been performed in ambient air and under N2 flow, both under different RH levels (from 6% to 40% RH). In addition, the influence of the dielectric film thickness, SiN deposition conditions and the substrate nature on the charging process have been investigated under different environment conditions. This has been done through depositing SiN films with different thicknesses ranges from 100nm to 400nm over bare silicon substrates and over evaporated Au layers and using both Low Frequency(LF) and High Frequency(HF) PECVD deposition modes.

Domaines: Micro et nanotechnologies/Microélectronique

Heiba Zaghloul, Bharat Bhushan, Patrick Pons, George Papaioannou, Fabio Coccetti, et al.. On the Impact of Relative Humidity and Environment Gases on Dielectric Charging Process in Capacitive RF MEMS Switches Based on Kelvin Probe Force Microscopy. AVS 57th International Symposium on Science and Technology of Materials, Interfaces and Processing (AVS 2010), Oct 2010, Albuquerque, United States. 1 page. ⟨hal-00670146⟩