ABSTRAT In this thesis, we focused on the fabrication and frequency-modulation of £f/4 mode dual-band solidly mounted resonators and filters. To accomplish the Bragg reflector, the RF/DC magnetron sputtering system with dual targets is adopted to deposit alternating layers of quarter-wavelength Mo and SiO2 thin films. We tune the fabrication parameters in accordance with the AFM measurement and achieve a low roughness of 2.9nm on a nine-layer reflector. The piezoelectric layer, aluminum nitride (AlN) thin films, is deposited on the Bragg reflector by means of reactive RF magnetron sputtering. We alter the distance between substrate and target is altered to deposit AlN with various c-axis tilting angle which results in longitudinal and shear acoustic waves at the same time. Furthermore, we use mass loading effect to modulate the resonance frequency and fabricate £k- ladder type filters. In various numbers of reflector layers, the optimum frequency response is obtained with return loss of -26dB, in a SMR on a 3.5 pair reflector. To investigate the relationship between longitudinal and shear resonance in different resonance frequency, we alter the c-axis tilting angle of AlN as well as various mass loading on the SMRs. Based on the experimental results, the ratio of longitudinal to shear resonance frequency remains a constant value despite various c-axis tilting angle of AlN and mass loading on the SMRs. In addition, the electromechanical coupling coefficient, Kt2, of shear resonance raises with the increase of c-axis tilting angle of AlN. Finally,we have successfully fabricated SMRs with frequency modulataion of 3,899.68 Hz-cm2/ng and £k-ladder type filters with 26 MHz bandwidth.

The 1/4£f dual-mode resonators made from c-axis-oriented aluminum nitride films grown on different conduction material have been studied in this thesis. The RF/DC sputter system is used to grow on layers of reflector. During the porcess, 3.5 pairs of Bragg reflector alternating with W and SiO2 are composed by Si substractor. To achieve 0.999 reflective rate, fabrication parameters are adjusted to make W films become £\-phase structurre. On the other hand, piezoelectric layers as well as reflective layers that using reactive RF magnetron sputtering system and means of off-axis are combined to deposite optimal resonators of shear mode quality factor (Q) resonatros. While changing the substract and target distance between various bottom electrode materials, including Si, W/Si, and Mo/Si could deposit AlN with various c-axis tilting angle which resulted in stimulating longitudinal and shear acoustic waves. Futhermore, the finding is used to discuss the growth mechanism of inclined AlN by TEM. The analysis of various distances of AlN films shows that column inclining angle and XRD-Rocking Curve £s will increase with distance. The quality of shear mode would be better when column and £s are highly shifed. About the influence on AlN deposites, AlN/Si was grown away from the center by 6 cm. AlN/Si column inclining angle is about 20 degree, and RMS could reach 2.63nm beneath. Uner AlN/W/Si, column incling angle is about 30 degree, and £s shift angle 4.14 degree, the shear mode quality factor of freaquency response is obtained to 262. Under AlN/Mo/W/Si, column incling angle would be 25.4 degree, and XRD are better-choosed c-aixsm, £s tilting angle shifs 6.72 degree, and the shear mode quality factor is obtained to 290. Film intersurface appears bigger misfit by TEM to obtain better shear mode.

In this study, we use the reactive rf magnetron sputtering method with deposition parameters of RF power of 370W, sputtering pressure of 15 mTorr, substrate temperature of 400¢J, nitrogen concentration (N2/N2+Ar) of 30% and 40%, to deposit highly c-axis orientation AlN thin films on Z-cut LiNbO3 and ST-cut quartz piezoelectric substrate, respectively. The material characteristics of AlN films deposited on Z-cut LiNbO3 and ST-cut quartz substrate with different thickness were obtained by means of the analyses of XRD, SEM and AFM. Besides, the interdigital transducers (IDTs) were fabricated on the bi-layers structure. The AlN film thickness of piezoelectric bi-layers structure was varied in order to discuss its effect on SAW devices and the temperature coefficient of frequency (TCF) of AlN. From the experimental results, it reveals that the center frequency and TCF of SAW filters increase with the increased AlN thin film thickness. Besides it can be concluded that poly-crystalline AlN exhibits a positive temperature coefficient of frequency (TCF).

In this thesis, we emphasized on fabrication and anlysis of 1/4 and 1/2 £f mode solidly mounted resonators. First, the reactive RF magnetron sputter used to deposit the highly c-axis-oriented aluminum nitride (AlN) piezoelectric films under different parameters. The various c-axis tilt angle also used it by altering the distance between substrate and target to investigate the characteristics. To accomplish the two modes of different pairs of Bragg reflector, the RF/DC sputter system is adopted alternating layers of quarter-wavelength Mo and SiO2 thin films by different sequence. Finally, depositing the highly c-axis-oriented AlN on reflectors to complete the 1/4 and 1/2 £f mode SMR. The AlN thin film achieve a very low roughness of 1.783nm under AFM measurement, the FWHM of XRD(002) peak is 3.507¢Xand SEM images also exhibit a highly oriented c-axis structure. The optimum frequency responses of 1/2 £f mode SMR is obtained with return loss of -57.23dB at 4 pairs reflectors,which for 1/4 £f mode SMR is -30.68dB at 3 pairs. The maximum electromechanical coupling coefficient (Kt2) of 1/2 £f mode SMR is 7.88%, but the quality factor (Q) of 1/4 £f mode SMR is 4231.29.

This Dissertation is a study of Switched Mode Power Supply (SMPS) miniaturization and how to effectively use the available technologies to achieve the ultimate goal of a reduced size without loss of functionality while maintaining a cost effective design. This research investigates several methods used to obtain low loss, highly compact power supplies. Within these constraints, the Dissertation investigates the issues of design, materials, and cost in order to design and achieve these miniaturized power supplies. This research addresses high performance ceramic, passive component integration. Three key issues; electrical characterization, thermal analysis and simulation, and material characterization, are examined in this work. Thick film passive components (capacitors and resistors) on AlN have been developed. Also, guidelines for the design implementation and steps necessary to integrate these passive components on prefired alumina (Al2O3) and aluminum nitride (AlN) ceramic surfaces, for power electronic applications, have been generated. The use of aluminum nitride, as a high performance ceramic substrate and the resulting issues concerning compatible inks, have been investigated. Since a sizable amount of heat is generated by power electronic circuits, the integrated components are analyzed with respect to tolerance and degeneration over a range of temperatures and frequencies. Thick film capacitors on the order of 120pF/mm2 with breakdown voltage ratings of 250V have been developed on prefired AlN. Resistors were developed with impedances ranging from 10W to 10MegW. Thermal measurements, of these resistors, show that the thermal conductivity of the aluminum nitride with passivation layer is two to three times that of alumina. Several versions of a typical SMPS boost circuit have been generated using Direct Bond Copper (DBC) on ceramic, Insulated Metal Substrate (IMS), Printed Circuit Boards (PCB), and prefired ceramic thick film technology. The integrated passive components developed are applied on prefired ceramic versions and compared to the DBC, IMS and PCB versions. A small daughter board consisting of the boost circuit control is introduced to further supplement miniaturization and reduce cost. The daughter board uses thick film technology with integrated thick film resistors. The design of the mother board, which houses the power boost section,can be designedand implemented on virtually any type of substrate (PCB, DBC, IMS, or conventional thick film). The fabrication and testing of each version is reported in this work. / Ph. D.

Les nanostructures 1D d'AlN promettent des nouvelles applications dans la technologie des semi-conducteurs, des antennes optiques et des résonateurs nanomécaniques. Elles peuvent également aboutir à l'évolution de nouveaux composants d'instrumentation. Cette étude explore deux voies originales pour élaborer des nanofilaments d'AlN en procédant à la mise en forme par électrofilage couplée à un procédé d'élaboration de céramique. Deux stratégies d'élaboration peuvent être considérées selon que le système initial contient de l'oxygène ou non. La maîtrise des conditions de mise en forme (paramètres d'électrofilage) ainsi que l'optimisation des solutions utilisées (teneur en polymère et en précurseur) et des traitements thermiques, ont permis d'obtenir des filaments de taille submicronique (entre 100 nm et 400 nm), ainsi que des tubes d'une grande pureté chimique et stables sous air jusqu'à 550°C. Il est démontré que la qualité des nano-objets d'AlN dépend de leur méthode de fabrication. L'étude basée sur deux méthodes de fabrication, l'une sous air et l'autre sous atmosphère contrôlée, permet de présenter les avantages et les inconvénients de chacune de ces deux approches, la première étant dite « low-cost » par rapport à la seconde / One-dimensional (1D) AlN nanostructures promise the achievement of new applications in semiconductor technology, optical antennas and nanomechanical resonators. They can also lead to the development of new components for instrumentation. This study explores two original methods to elaborate AlN nanofilaments performing shaping by electrospinning, coupled to a process for producing ceramic. Two strategies can be developed depending on whether the initial system contains oxygen or not. The control of the conditions of shaping (electrospinning parameters) and the optimization of the used solutions (polymer content and precursor) and heat treatments, allowed the obtainment of submicron sized filaments (between 100 nm and 400 nm), as well as tubes with a high chemical purity, and stable in air up to 550 °C. It is demonstrated that the quality of the AlN nano-objects depends on their method of elaboration. The study of the two used methods, one in air and the other under controlled atmosphere, can show the advantages and disadvantages of each of these two approaches, the first being "low-cost" comparing to the second

A pesquisa teve como objetivo recuperar as redes de solidariedade formadas por mulheres que mantiveram ou não vínculos orgânicos com a ALN (Ação Libertadora Nacional) e que prestaram os mais diversos tipos de colaboração a essa organização, participando não apenas dos levantamentos para ações armadas ou diretamente de sua execução, mas desempenhando também um papel primordial na retaguarda do movimento armado. A colaboração dessas mulheres foi parte também das transformações que se processaram na sociedade da época com relação à participação da mulher no espaço público. Na militância política, elas também introduziram mudanças na divisão de papéis entre os sexos e ressignificaram sua participação no interior dos grupos nos quais se incorporaram. Sua atividade foi fundamental para garantir a vida de pessoas, bem como permitir a continuação das atividades da organização no Brasil, em especial nos momentos mais repressivos da ditadura. Muito além de pequenos gestos, como se supõe, essas mulheres formaram uma força discreta, que deu aos militantes clandestinos a estabilidade necessária para continuarem na luta. / The research aimed to restore the solidarity networks formed by women who maintained or no organic links with the ALN (National Liberation Action), which provided the most diverse types of contributions to that organization, participating not only from surveys or directly to armed actions his execution, but also playing a pivotal role in the rear of the armed movement. The collaboration of these women was also part of the changes which were processed in the society of that time with respect to women\'s participation in public space. In political activism, they also introduced changes in the division of roles between the sexes, and resignify their participation within the groups of which it is incorporated. Its activity was essential to safeguard the lives of people as well as to enable continuation of the organization\'s activities in Brazil, especially in the most repressive dictatorship. Much more than a minor adjustment, as is supposed, these women formed a slight force, which gave the clandestine militants stability to continue the fight.

Les actionneurs piézoélectriques se distinguent par leurs faibles temps de réponse et leurs rapports déflexion/ tension d’actionnement élevés. Dans ces travaux, nous nous attacherons à optimiser la déformation de matériaux piézoélectriques. La première approche consiste à augmenter le champ dans la couche active et la seconde à optimiser les coefficients piézoélectriques du matériau. Pour répondre à des problématiques d’actionnement basse tension, des couches de nitrure d’aluminium (AlN) ultraminces ont été déposées et caractérisées. Le coefficient e31,eff s’est avéré être constant entre 800 et 50 nm d’épaisseur, à une valeur de -0,8 C/m², ce qui est proche de l’état de l’art. Le caractère piézoélectrique de l’AlN à une épaisseur de 12 nm a été mis en évidence. Toujours dans l’optique de travailler à champ électrique élevé, une étude visant à augmenter le champ de claquage du titano-zirconate de plomb (PZT) par insertion d’atomes de lanthane a été menée. Le champ de claquage est amélioré de 35% environ, sans que la permittivité diélectrique et les coefficients piézoélectriques ne soit dégradés. La seconde approche consiste à optimiser les coefficients piézoélectriques. Pour cela, le Titano Zircoate de Plomb a été étudié au voisinage de différentes transitions de phases. La transition morphotropique est particulièrement favorable au niveau piézoélectrique, avec un coefficient e31,eff qui atteint -18 C/m² hors champ et -27 C/m² sous champ. La problématique de blocage de parois de domaines a été abordée. La transition de Curie se manifeste principalement au niveau diélectrique, avec une permittivité relative qui atteint 2640 à 370°C, soit près du double de la valeur mesurée à température ambiante. Les pertes diélectriques diminuent entre 25°C et 280°C, pour atteindre 1,6 %. Afin de bénéficier d’une transition critique, du PZT fortement dopé au lanthane a été déposé.Un comportement relaxeur a été mis en évidence et un coefficient piézoélectrique induit d31 de -25 pm/V a été mesuré. Les matériaux développés dans cette thèse ouvrent des perspectives pour la réalisation de microactionneurs et notamment de têtes d’imprimantes jet d’encre. / Piezoelectric actuators exhibit low response times and high deflection/actuation voltage ratios. This PhD thesis aims at optimizing their strain values by increasing the applied field and the piezoelectric coefficients. To target low voltage issues, Aluminum Nitride (AlN) ultrathin layers were deposited and characterized. e31,eff coefficient was found to be constant between 800 and 50 nm, at a value as high as -0.8 C/m². Piezoelectric behaviour was also shown for 12 nm-thick AlN layers, by three different ways. Still in order to apply high electric fields, a study was carried out to improve Lead Zirconate Titanate (PZT) breakdown field, by inserting lanthanum atoms. Breakdown field was improved by approximately 35%, with no decrease of permittivity or piezoelectric coefficients. Another optimization approach consists in increasing the material’s piezoelectric coefficients. In this view, PZT was characterized around several phase transitions. Near morphotropic phase boundary, piezoelectric effect was found to be enhanced: e31,eff coefficient raises up to -18 C/m² at low field conditions and -27 C/m² in actuating conditions. Domain wall pining issue was also discussed. Near Curie transition, dielectric properties were found to be enhanced, with a dielectric constant rising up to 2640 at 370C, which is almost twice as high as room temperature value. Furthermore, dielectric loss decreases from 25C to 280C to reach 1.6%. To profit from a critic phase transition, highly Lanthanum doped PZT was deposited. Relaxor behaviour was shown and an induced piezoelectric coefficient d31 of -25 pm/V was measured. Materials developed in this PhD thesis can be used to realize microactuators and especially inkjet printheads.

Poursuivant l'essor des méta-matériaux micro-ondes et photoniques, les cristaux phononiques, organisations périodiques de matériaux acoustiquement différents présentant notamment des bandes d'arrêt, c'est-à-dire de plages de fréquences pour lesquelles aucun mode ne se propage dans la structure, laissent entrevoir des applications acoustiques hors de portée des technologies existantes. Dans cette thèse, nous visons des réalisations aux fréquences RF afin de viser des applications complémentaires des résonateurs ou des filtres acoustiques largement employés dans le domaine des transmissions sans fil. Nous avons tout d'abord développé un procédé de fabrication simple permettant de réaliser des cristaux phononiques à deux dimensions à l'échelle micrométrique sur membrane piézoélectrique, afin de rendre ces systèmes compatibles avec les composants à ondes de Lamb développés au CEA-LETI pour des applications de filtrage de canal dans des architectures de transmission sans fil faible consommation. Ce procédé a été utilisé pour réaliser des cristaux phononiques, ainsi que des résonateurs à ondes de Lamb, ou à ondes de volume et des structures plus complexes comme par exemple des filtres passe-bande. Une étude paramétrique des composants à ondes de Lamb nous a permis d'affiner notre maîtrise de ces dispositifs, ce qui nous a été utile pour la mise au point des lignes à retard permettant de caractériser les propriétés de transmission acoustique des cristaux phononiques. Du point de vue théorique, un modèle de simulation par éléments finis a été mis en place, dans un premier temps pour dimensionner les structures réalisées et prendre en compte les modifications apportées par la réalisation technologique. Nous avons ensuite réalisé des cristaux phononiques que nous avons caractérisés électriquement et optiquement, en collaboration avec l'Institut FEMTO-ST. Les mesures confirment la présence de bandes d'arrêt, aux fréquences attendues, mais d'une largeur a priori bien supérieure à celle prévue par la simulation. Une étude détaillée des diagrammes de bandes attribue ce phénomène à la présence de bandes sourdes dans le cristal ne pouvant être excitées par les transducteurs utilisés. Cet aspect est d'une importance critique dans le dimensionnement de cristaux phononiques en vue d'une utilisation dans des applications pratiques. / In the straight line of photonic and microwave meta-materials, phononic crystals are foreseen to enable novel acoustic applications that existing technologies cannot reach. These phononic crystals are periodic organisation of acoustically different materials exhibiting, for example, qtop bands, which means frequency ranges in which no wave can propagate in the structure. In this thesis we target RF frequencies in order to investigate applications complementary to the conventional resonators or filters widely used in mobile telecommunication systems. We developed a simple process flow to realise micrometric two-dimensional phononic crystals on a piezoelectric membrane. These structures are fabricated along with Lamb wave devices studied in CEA-LETI for channel filtering in low consumption wireless transmission architectures, and with bulk wave resonators or more complex structures like band-pass filters. A parametric study of Lamb wave resonators sharpens our knowledge on these devices, which allow us to design and fabricate delay lines to characterise acoustic transmission properties of phononic crystals. From a theoretical point of view we set up a simulation model using finite element method. This model was used to design the phononic crystal we realised, and to take into account the effects of the modifications brought by the technological realisation. We then fabricated phononic crystals, and electrically and optically characterised them, in collaboration with FEMTO-ST institute. Measurements confirmed the presence of band gaps at the targeted frequency, but over a wider frequency range than predicted by calculation. A detailed study of band diagrams is attributing this phenomenon to the presence of deaf bands, which cannot be excited by interdigitated fingers. This shows that the determination of these deaf bands is of critical importance in designing phononic crystals for practical applications.

A pesquisa teve como objetivo recuperar as redes de solidariedade formadas por mulheres que mantiveram ou não vínculos orgânicos com a ALN (Ação Libertadora Nacional) e que prestaram os mais diversos tipos de colaboração a essa organização, participando não apenas dos levantamentos para ações armadas ou diretamente de sua execução, mas desempenhando também um papel primordial na retaguarda do movimento armado. A colaboração dessas mulheres foi parte também das transformações que se processaram na sociedade da época com relação à participação da mulher no espaço público. Na militância política, elas também introduziram mudanças na divisão de papéis entre os sexos e ressignificaram sua participação no interior dos grupos nos quais se incorporaram. Sua atividade foi fundamental para garantir a vida de pessoas, bem como permitir a continuação das atividades da organização no Brasil, em especial nos momentos mais repressivos da ditadura. Muito além de pequenos gestos, como se supõe, essas mulheres formaram uma força discreta, que deu aos militantes clandestinos a estabilidade necessária para continuarem na luta. / The research aimed to restore the solidarity networks formed by women who maintained or no organic links with the ALN (National Liberation Action), which provided the most diverse types of contributions to that organization, participating not only from surveys or directly to armed actions his execution, but also playing a pivotal role in the rear of the armed movement. The collaboration of these women was also part of the changes which were processed in the society of that time with respect to women\'s participation in public space. In political activism, they also introduced changes in the division of roles between the sexes, and resignify their participation within the groups of which it is incorporated. Its activity was essential to safeguard the lives of people as well as to enable continuation of the organization\'s activities in Brazil, especially in the most repressive dictatorship. Much more than a minor adjustment, as is supposed, these women formed a slight force, which gave the clandestine militants stability to continue the fight.