ZnO nanofillers, with different morphologies, were synthesized by a facile aqueous sol-gel approach andembedded, at low concentration (i.e. 4 wt.%), into a UV-curable acrylic system. SEM observations showed ahomogeneous distribution of the fillers within the cured network. The different morphologies of ZnOnanostructures were found to significantly affect the thermo-oxidative stability and the glass transitiontemperature of the obtained UV-cured films. Microcantilevers, made of the prepared films with sputteredaluminum contact, were fabricated by using standard microfabrication technology and their piezoelectricresponse was investigated both at the resonance frequency and at lower frequency values. Despite the low ZnOcontent, all the UV-cured nanocomposite films showed interesting piezoelectric properties: in particular, thedevices containing flower-like nano-structures exhibited the highest root mean square voltage both at 150 Hzand at the resonance frequency (about 0.176 ± 0.001 and 0.914 ± 0.001 mV, respectively). In addition, thesedevices also showed maximum peak-peak voltage values at both the selected frequencies.

L'obiettivo di questo lavoro è la preparazione di nuovi ricoprimenti piezoelettrici impiegabili per applicazioni di "Energy Harvesting" ed in particolare come sistemi anti-intrusione e/o di sicurezza negli attraversamenti pedonali. I sistemi sono costituiti da una resina organica fotoreticolabile che funge da matrice e particelle micro- e nano- metriche di ossido di zinco (ZnO) a diverso rapporto di forma (aciculare, sferico, bipiramidale, flower-like) ottenute mediante sintesi sol-gel.Risultati preliminari hanno dimostrato la possibilità di reticolare mediante UV-curing le dispersioni di ZnO nella resina selezionata ottenendo un buona distribuzione di carica nella matrice polimerica. E' stata inoltre misurata la risposta piezoelettrica dei rivestimenti ottenuti che è risultata essere funzione dei parametri sperimentali adottati (morfologia e concentrazione della carica).

The objective of this paper is to study the morphology, structure, and composition, as well as the thermal-induced morphological, structural, and chemical changes of copper(Cu)/titanium nitride(TiN) bilayers versus Cu single layers, deposited on silicon substrates for microelectronic applications. These characterizations aimed to assess the reliability of Cu metallization for local interconnect and to investigate the barrier capability of TiN against Cu diffusion into the silicon (Si) substrate. Moreover, this paper provides a fundamental study of the temperature-induced interactions between Cu and Si, intermediated by the presence of a thin TiN layer. Cu thin films were sputtered onto Si substrates, with and without the interposition of thin TiN layers, and were successively annealed at temperature as high as 600. C. Different nitrogen flux percentages in the sputtering mixture (Ar + N-2) were used for the deposition of the barriers. X-ray diffraction (XRD) analyses were carried out in order to study the structural evolution of the layers, before and after the annealing. Scanning electron microscopy (SEM) observations gave information about the surface and cross section morphology, and spatially resolved energy dispersive X-ray Spectroscopy (EDS) profiles provided chemical information about the cross-sectional distribution of the atomic species and their possible interdiffusion. The barrier efficacy has been demonstrated by comparing the morphological and chemical modifications of the annealed Cu layers, with and without the presence of the TiN layer, and their effects on the electrical properties of the Cu films.