Die vorliegende Dissertation befasst sich mit der Bewertung eines Mehrfachschichtmodells für Permeationsbarrieren auf Basis einer detaillierten Charakterisierung der zugrunde liegenden Einzelschichten. Diese sind reaktiv gesputterte Oxidschichten als Barriereschicht und mittels Magnetron-PECVD abgeschiedene siliziumhaltige Plasmapolymerschichten zur Verwendung als Zwischenschicht. Zunächst werden die verschiedenen gesputterten Oxidschichten charakterisiert und verglichen. Die untersuchten Materialien sind Zinkoxid, Siliziumoxid, Zink-Zinn-Oxid, Aluminiumoxid und Titanoxid. Die wirkenden Permeationsmechanismen und die Ursachen für teils deutliche Unterschiede zwischen verschiedenen Materialien werden diskutiert. Während die Sauerstoffpermeation immer durch Punktdefekte in den Schichten bestimmt wird, muss bei der Wasserdampfpermeation von weiteren Permeationsmechanismen ausgegangen werden. Am Beispiel des Zink-Zinn-Oxids und des Aluminiumoxids wird anschließend die Abhängigkeit der Permeationseigenschaften von wesentlichen Prozessparametern wie Sputterleistung, Prozessdruck oder reaktiver Arbeitspunkt untersucht. Im zweiten Teil der Arbeit werden die Plasmapolymerschichten hinsichtlich ihrer Struktur- und Permeationseigenschaften charakterisiert und mit gesputtertem Siliziumoxid verglichen. Die Abhängigkeit der Permeationseigenschaften vom Kohlenstoffgehalt in den Schichten wird untersucht. Anhand der gewonnenen Ergebnisse werden abschließend sowohl die Sputterschichten als auch die mittels Magnetron-PECVD abgeschiedenen Schichten hinsichtlich ihrer Eignung für ein Barrieremehrfachschichtsystem bewertet. / The aim of this PhD-thesis is to evaluate a concept for a multilayer permeation barrier by a detailed characterization of the different constituent of the layer stack. The multilayer concept is based on reactively sputtered permeation barrier layers and an interlayer that is deposited by using a magnetron based plasma enhanced chemical vapor deposition (Magnetron-PECVD) process. In the first part of this thesis, different sputtered oxide layers are characterized and compared regarding their structural and surface properties as well as their water vapor and oxygen permeability. These oxide layers include the materials zinc oxide, silicon oxide, zinc-tin oxide, aluminum oxide and titanium oxide. The permeation mechanisms and reasons for significant differences in the water vapor and oxygen transmission rates in the different materials are evaluated and discussed. Oxygen permeation thereby is always dominated by defects in the layers. In contrast to that, additional permeation mechanisms can be assumed for water vapor permeation. The dependence of the gas permeation on sputter process parameters like plasma power, process pressure and reactive sputtering mode is evaluated for zinc-tin oxide and aluminum oxide layers. In the second part of this thesis, plasma polymer layers that are deposited using the Magnetron-PECVD process are characterized regarding their structure and surface roughness. Their water vapor and oxygen permeability is compared to the permeation through reactively sputtered silicon oxide layers. The dependence of the gas permeation on the atomic composition, in particular on the carbon concentration, is evaluated. Finally, both the sputtered oxide layers and the Magnetron-PECVD plasma polymer layers are evaluated regarding their usability in a multilayer stack for high permeation barrier applications.

Global warming and developments of alternative energy technologies have become important issues nowadays. Subsequently, the concept of energy harvesting is rising because of its ability of transferring waste energy into usable energy. Thermoelectric devices play a role in this field since there is tremendous waste heat existing in our lives, such as heat from engines, generators, stoves, computers, etc. Thermoelectric devices can extract the waste heat and turn them into electricity. Moreover, the reverse thermoelectric phenomenon has the function of cooling which can be applied to refrigerator or heat dissipation for electronic devices. However, the energy conversion efficiency is still low comparing to other energy technologies. The efficiency is judged by thermoelectric figure of merit (ZT), defined by Seebeck coefficient, electrical conductivity and thermal conductivity. In order to improve ZT, thin film materials are good candidates because of their structural effects on altering ZT.    Ca3Co4O9 thin films grown by reactive radio frequency magnetron sputtering followed by post-annealing process is studied in this thesis. Structural properties of the films with the evolution of elemental ratio (Ca/Co) of calcium and cobalt have been investigated. For the investigations, three samples having elemental ratio 0.82, 0.72, and 0.66 for sample CCO1, CCO2 and COO3, respectively, have been prepared. Structural properties of the films have been investigated by X-ray diffraction (XRD) θ-2θ and pole figure analyses. Surface morphology of the films has been investigated by scanning electron microscopic (SEM) analyses. The highly oriented and phase pure epitaxial Ca3Co4O9 thin films were obtained in the end.   Mixing of ScN and CrN to obtain ScxCr1-xN solid solution thin films by DC magnetron sputtering is the other task in this thesis. Growth of ScN and CrN thin films were studied first in order to get the best mixed growth conditions. The phase shifts between ScN (111) and CrN (111) peaks were observed in mixed growth films by XRD θ-2θ measurements, indicating the formation of ScxCr1-xN. Surface morphology of the films were investigated by SEM. The (111)-oriented ScxCr1-xN thin films with decent surface smoothness grown by DC magnetron sputtering at 600 °C in pure nitrogen with bias were developed.

Made available in DSpace on 2014-12-17T14:07:10Z (GMT). No. of bitstreams: 1 IgorON_DISSERT.pdf: 2261728 bytes, checksum: ec2c0dd089b3f051427a0e42ea972424 (MD5) Previous issue date: 2011-12-09 / The technique of surface coating using magnetron sputtering is one of the most widely used in the surface engineering, for its versatility in obtaining different films as well as in the micro / nanometric thickness control. Among the various process parameters, those related to the active species of the plasma are of the most fundamental importance in the mechanism and kinetics of deposition. In order to identify the active species of the plasma, parameters such as gas flow, pressure and density of electric power were varied during titanium coating on glass substrate. By flowing argon gas of 10, 20, 30, 40 and 50 sccm (cubic centimeters per minute) for each gas flow a sequential scan of the electric current of 0.10, 0.20, 0.30, 0.40 , 0.50 A. The maximum value of 0.50 A was chosen based both on literature data and on limitations of the equipment. The monitoring of plasma species present during the deposition was carried out in situ by the technique of optical emission spectroscopy (OES) through the spectrometer Ocean Optics USB2000 Series. For this purpose, an apparatus was developed to adapt the OES inside the plasma reactor to stay positioned closest to the target. The radiations emitted by the species were detected by an optical fiber placed behind the glass substrate and their intensities as a function of wavelength were, displayed on a monitor screen. The acquisition time for each condition of the plain parameters was related to the minima of spectral lines intensities due to the film formed on the substrate. The intensities of different emission lines of argon and titanium were then analyzed as a function of time, to determine the active species and estimate the thickness of the deposited films. After the deposition, the coated glasses thin films were characterized by optical transmittance through an infrared laser. It was found that the thickness and deposition rate determined by in situ analysis were consistent with the results obtained by laser transmittance / t?cnica de revestimento superficial utilizando magnetron sputtering ? uma das mais utilizadas pela engenharia de superf?cie, pela sua versatilidade na obten??o de diferentes filmes bem como no controle micro/nanom?trico de sua espessura. Dentre os v?rios par?metros do processo, aqueles relacionados com as esp?cies ativas do plasma s?o de fundamental import?ncia no mecanismo e cin?tica da deposi??o. Com o objetivo de identificar as esp?cies ativas do plasma, par?metros como fluxo de g?s, press?o de trabalho e densidade de pot?ncia el?trica foram variados durante o revestimento de tit?nio em substrato de vidro. Foi utilizado arg?nio com fluxos de 10; 20; 30; 40 e 50 sccm (cent?metro c?bico por minuto) e para cada fluxo de g?s uma varredura sequencial da corrente el?trica de 0,10; 0,20; 0,30; 0,40; 0,50A (amp?res). O valor de m?ximo de 0,50A foi escolhido com base em dados da literatura e limita??es do equipamento. O monitoramento das esp?cies do plasma presentes durante a deposi??o foi realizado "in situ", pela t?cnica de espectroscopia de emiss?o ?ptica (EEO) atrav?s do espectr?metro USB2000 Series da Ocean Optics. Para isso um aparato foi desenvolvido para adaptar o EEO dentro do reator de plasma de maneira que ficasse posicionado o mais pr?ximo poss?vel do alvo. As radia??es emitidas pelas esp?cies foram detectadas atrav?s de uma fibra ?ptica colocada por tr?s do substrato de vidro e suas intensidades, em fun??o do comprimento de onda, foram exibidas na tela de um monitor. O tempo de aquisi??o para cada condi??o de par?metro do plasma foi aquele em que a intensidade espectral deca?a para zero, devido ao filme formado no substrato. As intensidades de diferentes linhas de emiss?o de arg?nio e de tit?nio foram ent?o analisadas em fun??o do tempo, para determinar as esp?cies ativas e estimar a espessura dos filmes depositados. Ap?s a deposi??o, os filmes finos que revestiram os vidros foram caracterizados por transmit?ncia optica, atrav?s de um laser no infravermelho. Verificou-se que os valores da espessura e da taxa de deposi??o s?o determinada pela an?lise "in situ", foram coerentes com os resultados obtidos atraves da transmit?ncia por laser

Les travaux présentés dans cette thèse constituent une étude sur la possibilité de déposer par pulvérisation plasma des couches minces de TiN sur des fils d'acier inoxydable en défilement. Les aspects technologiques tels que la conception et la construction d'une ligne prototype capable de nettoyer et déposer sur toute la circonférence des substrats cylindriques en mouvement sont présentés. Le développement de procédé dans la chambre de nettoyage par micro-ondes a permis l'amélioration des performances du plasma en termes de densité et de température d'électronique, ce qui a conduit à une amélioration de l'efficacité de nettoyage de substrat en termes de degré de propreté et de temps de traitement requis. D'une manière similaire, le développement de procédé dans la chambre de dépôt a permis de mettre en évidence la limitation majeure du magnétron cylindrique inversée (ICM), soit la très haute température atteinte par le substrat pendant le procédé. Le calcul théorique a permis l'identification de la majeure contribution au chauffage du substrat, et, afin de la réduire, la mise en place d'une solution technique consistant en électrodes supplémentaires, indépendamment polarisées. L'impact de la polarisation des électrodes supplémentaires est présenté en termes de paramètres de procédé (confinement du plasma, redistribution des courants, potentiel de la cible, modes de pulvérisation, temps de traitement plus permis, etc.), et, également, en termes de propriétés de couches déposées (vitesse de dépôt, profil d'épaisseur, composition et stœchiométrie). Basés sur les résultats obtenus dans le magnétron actuel, plusieurs possibilités d'améliorer encore les performances d'une nouvelle chambre de dépôt sont discutées. / This thesis represents a study of the possibility to sputter - deposit titanium nitride thin films on moving stainless steel wires. Technological aspects such as the conception, design and construction of a prototype tool capable of in-line cleaning and deposition all around the circumference of moving cylindrical substrates are presented. The process development in the microwave cleaning chamber allowed the improvement of the plasma performance in terms of density and electron temperature, which lead to improvement of the substrate cleaning efficiency in terms of degree of cleanliness and required process time. Similarly, the process development in the deposition chamber permitted to highlight the major limitation of the inverted cylindrical magnetron (ICM), which is the very high temperature, the substrate reaches during process. Theoretical calculation allowed the identification of the major contribution to substrate heating, and a technical solution consisting of independently biased additional electrodes is proposed in order to reduce it. The impact of the additional electrodes polarization is discussed both in terms of process parameters (plasma confinement, electron current redistribution, target voltage, sputtering modes, longer allowable process time, etc.), and in terms of films properties (deposition rate, thickness profile, composition and stoichiometry). Based on the results obtained in the present ICM, several possibilities to improve the performance of a new magnetron are discussed.

Submitted by Ziani DE SOUZA SCHIABER (zianisouza@yahoo.com.br) on 2016-05-02T20:43:07Z No. of bitstreams: 1 Tese_Final_Ziani_Schiaber.pdf: 4224142 bytes, checksum: 63114f480403729da0d811c82872c3cc (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-04T19:24:06Z (GMT) No. of bitstreams: 1 schiaber_zs_dr_bauru.pdf: 4224142 bytes, checksum: 63114f480403729da0d811c82872c3cc (MD5) / Made available in DSpace on 2016-05-04T19:24:06Z (GMT). No. of bitstreams: 1 schiaber_zs_dr_bauru.pdf: 4224142 bytes, checksum: 63114f480403729da0d811c82872c3cc (MD5) Previous issue date: 2016-04-19 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nanosestruturas de GaN destacam-se devido à baixa densidade de defeitos e consequentemente alta qualidade estrutural e óptica quando comparadas ao material em forma de filme. O entendimento dos mecanismos de formação de nanofios e nanocolunas de GaN por diferentes técnicas é fundamental do ponto de vista da ciência básica e também para o aprimoramento da fabricação de dispositivos eletrônicos e optoeletrônicos baseados nesse material. Neste trabalho discorre-se sobre a preparação e caracterização de nanofios e nanoestruturas de GaN pelas técnicas de epitaxia por magnetron sputtering e epitaxia por feixe molecular em diferentes tipos de substratos. Pela técnica de epitaxia por magnetron sputtering foram obtidos nanocristais e nanocolunas de GaN, além de uma região com camada compacta. Visando criar uma atmosfera propícia para o crescimento de nanoestruturas de GaN não coalescida, atmosfera de N2 puro e um anteparo, situado entre o alvo e o porta-substratos, foram utilizados. O anteparo causou diferença no fluxo incidente de gálio no substrato, ocasionando a formação de diferentes tipos de estruturas. A caracterização das amostras se deu principalmente através de medidas de microscopia eletrônica de varredura, difração de raios X e espectroscopia de fotoluminescência. As nanocolunas, de 220 nm de altura, foram formadas na região distante 2 mm do centro da sombra geométrica do orifício do anteparo e apresentaram orientação [001] perpendicular ao substrato, comumente encontrada em nanofios de GaN depositados por MBE. Em relação aos nanofios obtidos pela técnica de MBE, investigou-se a possibilidade de controlar a densidade de nanofios através de uma camada de Si sobre o GaN–Ga polar visando inibir a coalescência. Diferentes quantidades de Si foram depositadas e a densidade dos nanofios foi diferenciada significativamente. Os nanofios apresentaram densidade média de 108 nanofios/cm2 com 0,60 nm de espessura da camada de Si. Espessuras menores não resultaram no crescimento de nanofios, porém espessuras superiores causaram uma alta densidade de nanofios de 1010 nanofios/cm2 que permaneceu constante, independentemente do tempo de deposição. Medidas de polo por difração de raios X evidenciaram que os nanofios nuclearam-se orientados e em uma camada cristalina de Si ou SixNy. Experimentos de ataque químico com KOH indicaram a polaridade N para o nanofio e as medidas de difração por feixe convergente confirmaram a polaridade de N para o nanofio e Ga para a buffer layer. Os resultados obtidos neste trabalho permitiram um melhor entendimento da nucleação e dos mecanismos de formação de nanoestruturas de GaN, viabilizando maior controle das características dessas nanoestruturas produzidas. / GaN nanowires and nanocolumns stand out due to the low defect density and high structural and optical quality compared to the corresponding thin films. The understanding of the formation mechanism of the different GaN structures using different techniques is critical to improving the manufacture of the electronic and optoelectronic devices based on this material. This thesis focuses on the preparation and characterization of GaN nanowires and nanostructures. The molecular bem epitaxy (MBE) and magnetron sputtering epitaxy (MSE) were used and different substrates were tested. Concerning GaN nanocrystals and nanocolumns obtained by MSE, optimization of the deposition conditions was necessary in order to produce non-coalesced GaN nanostructures. The best conditions were: pure N2 atmosphere, silicon substrate, and a perforated screen placed between the target and the substrate holder. The later produced differences on the Ga flow to the substrate, inducing the formation of different structures, depending on the position of growth spot. Samples were characterized using scanning electron microscopy, X-ray diffraction and photoluminescence spectroscopy. Nanocolumns were observed, mainly in sites corresponding to a disc of radius 2 mm from the geometric centre of the hole. The columns were oriented with the GaN [001] axis perpendicular to the Si (111) substrate surface, situation which is commonly found in GaN nanowires deposited by MBE. Regarding the nanowires prepared by MBE technique, in order to inhibit coalescence and to investigate the possibility of controlling the numerical density of nanowires, we have used Si cap layers on top of the Ga-polar GaN buffer layer. Different amounts of Si have been deposited, and the density of the nanowires was significantly modified. With Si layer thickness of 0.60 nm, the nanowires had an average density of 108 nanowires/cm2 . Lower thickness did not result in the growth of nanowires, but higher thickness caused a high density of nanowires of 1010 nanowires/cm2 which remained constant regardless of the deposition time. X-ray diffraction pole figures showed that the different nanowires grown up in oriented fashion in a crystalline layer of Si or SixNy. Etching with KOH indicated N polarity for the grown nanowires, in spite of the fact that they were grown using Ga polar GaN buffer layers. Measurements by convergent beam electron diffraction confirmed the N polarity to the nanowire and Ga polarity for the buffer layer. Aspects obtained in this study allowed a better understanding of nucleation and nanostructures formation mechanisms of GaN, enabling greater control of the characteristics of these nanostructures produced. / FAPESP: 2011/22664-2 / FAPESP: 2013/25625-3

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This master thesis performs the analysis and design of an AC-DC converter with high voltage gain to be used to supply a magnetron in a microwave generation system. The converter topology is chosen so as to enable input power control, operation with high power factor and with possibility of wide variation in the effective voltage input, so that the converter operates in the universal 100-240 V effective voltage range. The topology consists of a controlled type half-bridge rectifier at the entrance, responsible for the current control and diferencial voltage balance on the DC link capacitors and an isolated DC-DC half-bridge converter with high voltage gain, which operates with a fixed duty cycle. The design of passive and active elements of AC-DC converter are presented and the discrete control to implement a prototype that operates with input power up to 800 W is performed. The controllers are implemented in a low-cost 32-bit and fixed point arithmetic microcontroller. Experimental results to validate the designed controllers are obtained for various power reference values, evaluating the converter for practically all operational range. / A presente dissertação de mestrado realiza a análise e o projeto de um conversor CA-CC de elevado ganho de tensão para ser utilizado na alimentação de um magnetron em um sistema de geração de micro-ondas. A topologia do conversor é escolhida de forma a possibilitar o controle da potência de entrada, operação com elevado fator de potência e com possibilidade de grande variação na tensão eficaz da entrada, de forma que o conversor opere na faixa de tensão universal eficaz de 100 a 240 V. A topologia é composta por um retificador meia-ponte na entrada, responsável pelo controle de corrente e equilíbrio das tensões no barramento CC, e por um conversor CC-CC meia ponte isolado na saída com elevado ganho de tensão, que opera com razão cíclica fixa. O projeto dos elementos passivos e ativos do conversor CA-CC são apresentados e o controle discreto para implementação de um protótipo que opera com potência de entrada de até 800 W é realizado. Os controladores são implementados em um microcontrolador de baixo custo de 32 bits e operação aritmética de ponto fixo. Resultados experimentais para validação dos controladores projetados são obtidos, para vários valores de referência de potência, avaliando o conversor para praticamente toda sua faixa de operação.

Nesse trabalho foram fabricados filmes finos de TiO2 por RF magnetron sputtering reativo sobre substrato de silício (1 0 0). A pressão parcial do oxigênio na câmara foi variada de 5 a 100% em relação ao argônio. Após a deposição os filmes foram submetidos a tratamento térmico em atmosfera de oxigênio. A estequiometria dos filmes e o perfil de profundidade foram obtidos por RBS. A estrutura cristalina foi obtida por XRD. As propriedades ópticas foram obtidas por interferometria e reflectância e as elétricas por meio das curvas C-V. Os valores de espessura dos filmes sem tratamento térmico aumentaram aproximadamente 41% com o aumento do oxigênio na câmara de deposição. Essa variação está ligada ao aumento da eficiência do sputtering do alvo. Os índices de refração dos filmes sem tratamento térmico se mantiveram dentro de um intervalo de aproximadamente 2,3 a 2,4. A diminuição do band gap com o tratamento térmico é consequência da mudança de fase cristalográfica de anatase para rutila. A estequiometria TiOx dos filmes antes do tratamento térmico apresentaram valores de x entre 2,0 e 2,4. A espessura em TFU dos filmes aumentou com o percentual de oxigênio na câmara. As amostras que receberam tratamento térmico apresentaram difusão de titânio na interface do substrato e incorporação de oxigênio no filme. Os valores da constante dielétrica aumentaram com o percentual de oxigênio na câmara, em contraposição com o efeito do tratamento térmico que diminuiu o valor. Todos os resultados observados são coerentes do ponto de vista da mudança de fase anatase rutila e aumento do percentual de oxigênio na câmara. / In this work thin films of TiO2 were produced by reactive RF magnetron sputtering on silicon substrate (1 0 0). The oxygen partial pressure in the chamber was varied from 5 to 100% in relation to argon. After deposition the films were submitted to thermal treatment under an oxygen atmosphere. The stoichiometry of the films and the depth profile were obtained by RBS. The crystal structure was obtained by XRD. Its optical properties were obtained by interferometry and reflectance and the electrical were obtained by means of the C-V curves. The thickness values of films without heat treatment increased approximately 41% with the increase of oxygen in the deposition chamber. This variation is linked to the increased sputtering efficiency of the target. The refractive indexes of films without heat treatment remained within a range of about 2.3 to 2.4. The decrease of the band gap with the heat treatment is a consequence of the change of crystallographic phase from anatase to rutile. The TiOx stoichiometry of the films before the heat treatment showed values of x between 2.0 and 2.4. The TFU thickness of the films increased with the percentage of oxygen in the chamber. The samples that received heat treatment shows diffusion of titanium at the interface of the substrate and incorporation of oxygen in the film. The values of the dielectric constant increased with the percentage of oxygen in the chamber, as opposed to the effect of the thermal treatment that decreased the value. All the results observed are consistent from the point of view of the anatase - rutile phase transition and the increase in the oxygen percentage in the chamber.

The magnetic field is a key feature that distinguishes magnetron sputtering from simple diode sputtering. It effectively increases the residence time of electrons close to the cathode surface and by that increases the energy efficiency of the discharge. This becomes apparent in high power impulse magnetron sputtering (HiPIMS) discharges, as small changes in the magnetic field can result in large variations in the discharge characteristics, notably the peak discharge current and/or the discharge voltage during a pulse. Here, we analyze the influence of the magnetic field on the electron density and temperature, how the discharge voltage is split between the cathode sheath and the ionization region, and the electron heating mechanism in a HiPIMS discharge. We relate the results to the energy efficiency of the discharge and discuss them in terms of the probability of target species ionization. The energy efficiency of the discharge is related to the fraction of pulse power absorbed by the electrons. Ohmic heating of electrons in the ionization region leads to higher energy efficiency than electron energization in the sheath. We find that the electron density and ionization probability of the sputtered species depend largely on the discharge current. The results suggest ways to adjust electron density and electron temperature using the discharge current and the magnetic field, respectively, and how they influence the ionization probability.

A relativistic magnetron (RM) is a high-power microwave (HPM) source. The main objective of the RM is to generate directed electromagnetic pulses with high power, which can be used in e.g. HPM weapons and for electromagnetic compatibility testing. These pulses can disturb or damage electronic equipment. One of the main challenges when designing an RM is to generate the advantageous TE11 wave mode to the circular waveguide and antenna with high efficiency and peak power. This thesis investigates a new design of the RM, developed at the Swedish Defence Research Agency (FOI), referred to as the FOI magnetron. This design is based on the A6-magnetron and employs four large and two small cavities in the diffraction output of the RM, compared to the conventional design that has six identical cavities. The FOI magnetron has previously shown results that indicate the possibility of generating the TE11 wave mode. In this thesis, a literature study was performed to better understand the governing physical laws of the RM. This was followed by parametric studies using the ​​particle-in-cell code MAGIC3D for simulating the RM. To validate the simulation models, a model of a conventional RM was constructed and the results were compared against the published simulation results by Daimon and Jiang (2008).  Lastly, different geometrical properties, applied magnetic field, and applied voltage of the FOI magnetron were studied to see how they impacted the RM performance. Apart from the diffraction output, the geometry of the interaction region was studied to investigate the effect on frequency and power. The goal was to generate a clean TE11 mode in the waveguide of the RM with high efficiency. The validation yielded results that were in good agreement with the ones obtained by Daimon and Jiang (beam-to-microwave efficiencies of 37% and 36% respectively). The parameter studies of the FOI magnetron gave results that indicate a clean TE11 mode with a beam-to-microwave efficiency of ∼35% and peak powers up to 1 GW at frequencies of approximately 2.5 GHz. The studies on the interaction region showed that a shift of approximately 0.12 GHz was possible when making the rear part of the interaction region 4.5 cm longer. It was found that the length of the front of the interaction region can to some extent affect the output power. Lastly, it was found that a fraction of the output power (∼10−17%) that leaves the interaction region propagates back toward the input region and the voltage source.

Neste trabalho foram realizadas algumas deposições de filmes de Nitreto de Titânio sobre substrato de aço inoxidável. Foi utilizado o processo conhecido como triodo magnetron sputtering. Os parâmetros de deposição foram mantidos entre as deposições, exceto pela voltagem de bias no substrato, que foi variada de uma deposição para outra. Medições in-situ das tensões residuais no filme depositado foram realizadas. As medições foram feitas através do método da curvatura do substrato, utilizando-se um sensor capacitivo posicionado dentro da câmara de deposição. Embora o dispositivo não tenha sido capaz de quantificar os valores de tensão, foi possível identificar a natureza das mesmas, indicando se elas são de caráter trativo ou compressivo. Comprovou-se a possibilidade do uso de sistemas capacitivos para medições em sputtering. Observou-se que os filmes depositados apresentaram tensões de caráter trativo durante as deposições. / In this work, a series of depositions of titanium nitride thin films was conducted in a triode unbalanced magnetron sputtering chamber. Similar parameters were selected during each deposition, except for the substrate bias voltage, which was different for every deposition. An in-situ measurement of film residual stresses was carried out as the depositions proceeded. This measurement was based on substrate curvature, which was assessed by a home-built capacitive sensor positioned inside the sputtering chamber. Although the measurement device was not able to quantify the stress values, it was possible to identify if they were tensile or compressive. It was proved the possibility of using capacitive measurement devices in sputtering processes. It was possible to observe that the films underwent tensile stresses during the deposition.