A study on controllable aluminium doped zinc oxide patterning by chemical etching for MEMS application

This present work reports on the study of controllable aluminium doped zinc oxide (AZO) patterning by chemical etching for MEMS application. The AZO thin film was prepared by RF magnetron sputtering as it is capable of producing uniform thin film at high deposition rates. X-Ray diffraction (XRD) and atomic force microscopy (AFM) characterization were done to characterize AZO thin film. The sputtered AZO thin film shows c-axis (002) orientation, low surface roughness and high crystalline quality. To pattern AZO thin film for MEMS application, wet etching was chosen due to its ease of processing with few controlling parameters. Four etching solutions were used namely: 10 % Nitric acid, 10 % Phosphoric acid, 10 % Acetic acid and Molybdenum etch solutions. For the first time, chemical etching using Molybdenum etch that consist of a mixture of CH3COOH, HNO3 and H3PO4 was characterized and reported. The effect of these acidic solutions on the undercut etching, vertical and lateral etch rate were studied. The etched AZO were characterized by scanning electron microscopy (SEM) and stylus profilometer. The investigations showed that the Molybdenum etch has the lowest undercut etching of 7.11 µm, and is highly effective in terms of lateral and vertical etching with an etch ratio of 1.30. Successful fine patterning of AZO thin films was demonstrated at device level on a surface acoustic wave resonator fabricated in 0.35 μm CMOS technology. The AZO thin film acts as the piezoelectric thin film for acoustic wave generation. Patterning of the AZO thin film is necessary for access to measurement probe pads. The working acoustic resonator showed resonance peak at 1.044 GHz at 45.28 dB insertion loss indicating that the proposed Molybdenum etch method does not adversely affect the device’s operating characteristic

Simulation Methods of BAW Resonators and Filters for Integration in a Complete UMTS Transmitter or in Space Applications

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Tunable micro-machined combine filter.

International audienc

Simulations, conception et réalisation de filtres piézoélectriques

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tunable volumic resonator at 150 GHz using MEMS technology

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FBAR Filters for Space Application Based on LiNbO3 Membrane

Film bulk acoustic resonator (FBAR) usually use for filter application, can be used to address aerospace filter application which need large band. Then, it needs to use piezoelectric material with high electromechanical coupling coefficient. So we use LiNbO3 cut YXl/36 which have coupling coefficient for longitudinal mode of 37.5%

Solutions planaires pour filtrage submillimétrique

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Création d'une bibliothèque de ressources en ligne pour les enseignants d'IUT GMP

International audienceCet article présente la démarche de création d'une bibliothèque de ressources en ligne pour les enseignants d'IUT GMP. Il interroge dans un premier temps la granulométrie des ressources et la structuration de la bibliothèque : entrée par compétences, organisation autour d'une séance en présentiel, formulation par acquis d'apprentissage. Une première enquête réalisée auprès de 735 enseignants d'IUT permet de confronter les choix retenus. Dans un deuxième temps, la procédure d'élaboration de ces ressources par les équipes pédagogiques disciplinaires est présentée puis interrogée par une deuxième enquête menée auprès des acteurs du projet