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Abstract

In this paper, the impact of double-wall carbon nanotubes (DWCNTs) concentration within BenzoCycloButen (BCB) composites on electromagnetic properties is evaluated and modeled with coplanar test structures. It is demonstrated that only 0.37wt. % of DWCNT concentration increases the line losses level by more than a decade over a large frequency range. The resulting engineerable composite brings to RF-designer a novel degree of freedom to design and optimize microwave innovative components.

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Abstract

This paper introduces the use of germanium as resistive material in RF MicroElectroMechanical (MEMS) devices. Integrated resistors are indeed highly required into RF MEMS components, in order to prevent any RF signal leakage in the bias lines and also to be compatible with ICs. Germanium material presents strong advantages compared to others. It is widely used in microtechnologies, notably as an important semi-conductor in SiGe transistors as well as sacrificial or structural layers and also mask layer in various processes (Si micromachining especially). But it also presents a very high resistivity value. This property is particularly interesting in the elaboration of integrated resistors for RF components, as it assures miniaturized resistors in total agreement with electromagnetic requirements. Its compatibility as resistive material in MEMS has been carried out. Its integration in an entire MEMS process has been fruitfully achieved and led to the successful demonstration and validation of integrated Ge resistors into serial RF MEMS variable capacitors or switches, without any RF perturbations.

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Abstract

This paper presents the design and fabrication of an impedance tuner integrated thanks an RF-MEMS technology which is fully compatible with IC. The developed technology aims to fabricate RF-MEMS devices which are able to handle medium RF-power and also targets to be compatible with IC integration. Concerning the design, we have defined an appropriate methodology, specifically developed for RF-MEMS devices, which takes into account the large dispersion on the RF-MEMS contact quality and then down state capacitor value, and the values of generated impedances that we want as large as possible. The prospective of this work is to associate monolithically a power amplifier with this high Q (and then low losses) tuner in order to be able to tune the PAE or even the operating class.

Abstract

This paper presents the fabrication and experimental results of capacitive MEM switches with a carbon nanotubes (CNT) based dielectric for the first time to our knowledge. Double wall nanotubes (DWNT) have been incorporated in the switch silicon nitride dielectric to modify its properties regarding the charging effect. The impact of the CNT density on the MEMS reliability has been demonstrated: a switch lifetime enhancement greater than two orders of magnitude has been achieved.

Résumé

Cet article présente une première étude du polymère BenzoCycloButène (BCB) modifié par l'ajout de nanotubes de carbone (NTCs) pour des utilisations aux fréquences micro-ondes. La suspension de NTCs dans du T1100 (solvant du BCB) est composée de 85% de NTCs métalliques et environ 15% de semi-conducteur. La mis en place des concentrations de 0%, 0.06% et 0.16% de NTCs dans le BCB, nous a permis de mesurer les paramètres S pour ensuite extraire les paramètres électrique à et µ reff. Le mélange des NTCs modifie la conductivité et sa permittivité de notre polymère d'un facteur 5.