Qualité et Fiabilité des Commutateurs MEMS-RF pour des Applications Spatiales

The thesis deals with reliability of tiny electro-mechanical components called MEMS. MEMS stands for Micro-Electro-Mechanical Systems. These components, designed for switching applications, are suitable candidates for telecommunications due to their low power consumption, Radio-Frequencies (RF) performances, compactness and lightness. A MEMS is fabricated using processes of integrated circuit manufacturing that makes its cost relatively low. Few of these components are commercially available and more are expected to be in the market as soon as reliability issues will be solved. Reliability issues studied in the thesis regard mechanical creep and acceleration factors. The mechanical creep occurs in our suspended structures whilst enduring a constant force, it results in deformation of structures and shift of parameters. Two innovative test benches are developed to assess mechanical creep in RF-MEMS switches. The acceleration factors are keys to conduct accelerated testings and predict lifetime of RF-MEMS switches. Parameters such as bias voltage, input-to-output voltage, temperature are varied to assess lifetime of switches and extract these acceleration factors.Ce manuscrit traite de la fiabilité de micro-composants électro-mécaniques que l'on appelle des MEMS (Acronyme anglais signifiant Micro-Electro-Mechanical Systems). Les MEMS sont utilisés dans un grand nombre de domaines et le domaine qui nous concerne est celui des télécommunications. Plus précisément, notre domaine de travail se situe autour des radio-fréquences où les MEMS vont principalement réaliser des fonctions de commutation. On appellera ainsi nos composants des MEMS-RF, RF signifiant Radio-Fréquence. Dans ce domaine, les MEMS sont des candidats à fort potentiel grâce à une faible consommation de puissance, leur performance dans le domaine RF, leur encombrement et leur poids. De plus, en utilisant un procédé de fabrication dérivé de celui des semi-conducteurs, leur coût de production reste relativement faible. Dans ce manuscrit, on s'intéresse à la fiabilité de ces composants car c'est le dernier verrou avant une éventuelle industrialisation. Les principaux mécanismes de défaillance sont abordés dans une première partie, puis ce manuscrit se concentre sur l'étude du fluage mécanique et des facteurs d'accélération de modes de défaillance. On verra notamment l'influence de la température et des conditions de fonctionnement sur la durée de vie des commutateurs

Demonstration of the Influence of the Operating Parameters of the Operation of Ohmic Contact Micro Switches

Journées Nationales du GDR Micro Nano Systèmes - Micro Nano Fluidiqu

Novel Technique based on Monitoring contact resistance to assess creep in ohmic RF MEMS switches

International audienc

Asymmetrical mechanical design for bouncing suppression in RF-MEMS switches

International audienceContact bouncing is among the most critical phenomenon reducing RF-MEMS reliability. This paper shows that very simple changes in switch design permit suppression of contact bouncing upon closure. The proposed asymmetrical design gets two dimples in contact with substrate electrodes successively, instead of simultaneously. This helps the dissipation of kinetic energy and prevents contact re-opening. On top of preliminary ageing prevention, the structure can handle more actuation voltage and then have more contact force compared to symmetrical structures. Experimental demonstration is presented on metal contact switches with more than 2mN contact force, one symmetrical with significant bouncing and the other asymmetrical without any bouncing clearly show the relevance of the approach

Mechanical nanogap switch for low-power on-board electronics

International audienceThis paper presents the design fabrication and measurement of a nanogap radio frequency microelectromechanical system (RF MEMS) metal-contact switch. The prosed device generates a relatively high contact force with a low actuation voltage using a dielectric layer between the actuation electrode and the moveable beam. The actuation voltage is decreased with good reliability of the device by scaling down the gap. Beam geometry optimization allowed reaching 126 micronewtons contact force with only 10 V bias voltage. The fabricated miniature switch (80 × 50 × 0.95 µm) has indeed a pull-down voltage of 6 V and a contact resistance <2 Ω with 10 V bias applied. By measuring the S-parameters, the up-state capacitance has been fitted to 22 fF. The remarkable figure-of-merit Ron × Cup = 44 fs reflects the good performance of the device. A cycling test showed the device operated for 90 min without any charging problem noted

Mechanical Nano gap Switch for Low Power On-board Electronics

International audienc

High Power Handling Low-Voltage RF-MEMS Switched Capacitors

International audienc

An All-Metal Large Contact Force RF-MEMS Relay for Space Applications

International audienc

RF-MEMS Tunable SIW Filter with 16-state Digital Responses

International audienc

Simple Creep Parameters Extraction in Metal Contact RF-MEMS Switches

International audienc