%0 Conference Paper %A Clement Lorenzo, Marta %A Olivares Roza, Jimena %A Iborra Grau, Enrique %A González Castilla, Sheila %A Sangrador García, Jesús %A Rimmer, Nick %A Rastogi, A. %A Ivira, B. %A Reinhardt, Alexandre %B 22nd European Frequency and Time Forum (EFTF) 2008 %C Toulouse, Francia %D 2008 %F upm:3928 %I Braunschweig %T Aluminium Nitride Solidly Mounted BAW Resonators with Iridium Electrodes %U https://oa.upm.es/3928/ %X In this work we investigated the performance of aluminium nitride (AlN)-based solidly mounted resonators (SMR) made with iridium (Ir) bottom electrodes. Ir/AlN/metal stacks were grown on top of insulating Bragg mirrors composed of alternate λ/4 layers of silicon oxi-carbide (SiOC) and silicon nitride (Si3N4).Ir electrodes of various thicknesses were electron-beam evaporated on different adhesion layers, which also acted as seed layers. AlN was deposited by sputtering after conditioning the Ir electrode by a soft-etch with Ar+ ions, which was essential to achieve high quality AlN films. The structure and morphology of the different layers were analysed by x-ray diffraction (XRD) and atomic force microscopy (AFM). The frequency response of the SMRs was assessed by measuring the input scattering parameterS11 with a network analyzer. The experimental results were fitted to the Butterworth-Van Dyke circuital model. The effective electromechanical coupling factor k2eff, and the quality factor Q of the resonators were derived from the experimental data. The influence of the thickness, crystal quality and roughness of the Ir bottom electrodes on the performance of the resonators was investigated.