No description available.

Um novo processo de fabricação de dispositivos de emissão de campo (FE) em silício (Si) é apresentado nesta tese, baseado na potencialidade de utilização da técnica de microusinagem denominada HI-PS (Hydrogen Ion Porous Silicon), que trata da combinação entre processos de implantação de hidrogênio e silício poroso. Por meio do procedimento proposto, foram obtidos dispositivos com 2500 emissores (micropontas de Si) integrados e não integrados ao anodo e contidos em uma área de 2,8 x 2,8 mm² (3,2.10\'POT.4\' pontas/cm²). As micropontas de Si fabricadas apresentaram altura de 10 µm, com diâmetro do ápice em torno de 150 nm. A separação entre os emissores (50 µm), na configuração não integrada dos dispositivos, foi limitada pela resolução da máscara litográfica utilizada. Foram propostas etapas de otimização estrutural das micropontas após sua formação, e aplicadas tanto na configuração do sistema anodo-catodo integrado como não integrado. Como resultado destas etapas, constatou-se a redução do ápice das microestruturas para dimensões inferiores a 100 nm. Os dispositivos FE integrados foram obtidos com uma distância de separação entre o anodo e o catodo de aproximadamente 12 µm, distância definida pelas dimensões da máscara litográfica, porém não limitada pelo processo aplicado. Destacam-se, entre as vantagens da utilização da técnica HI-PS em relação às tecnologias usuais de manufatura dos dispositivos FE, a baixa complexidade do processo proposto e a utilização de apenas uma etapa litográfica para obtenção do sistema anodo-catodo integrado e auto alinhado. Para efetuar as caracterizações dos dispositivos, foram implementados uma câmara de vácuo específica, que permite alterar a distância entre as estruturas do anodo e do catodo não integradas, sem a necessidade de se retirar a amostra da câmara, e três sistemas para ensaios elétricos, sendo um destes sistemas desenvolvido especificamente para caracterização elétrica de dispositivos FE. As caracterizações elétricas foram efetuadas por meio de curvas I-V, I-t e V-d, sendo esta última utilizada para extrair o campo elétrico macroscópico E, que foi utilizado como parâmetro de comparação entre amostras submetidas a diferentes processos de otimização estrutural e de recobrimento superficial dos emissores por Al. Todas as amostras caracterizadas apresentaram variação de corrente exponencial com o potencial aplicado, de acordo com o esperado pela teoria proposta por Fowler-Nordheim (F-N). Dispositivos com otimização estrutural ou deposição de Al apresentaram melhores características de emissão (menor valor de E), de acordo com o aprimoramento do modelo de F-N sugerido na literatura para superfícies otimizadas. Constatou-se, pelos gráficos de F-N, o comportamento diferenciado dos emissores de Si tipo p em comparação com outros materiais, estabelecendo uma relação entre as variações da inclinação da curva traçada às distintas fontes de elétrons do Si. Frente aos resultados obtidos, conclui-se que a técnica Hi-PS é altamente promissora para fabricação de emissores microusinados em Si para aplicações em dispositivos FE. / This thesis presents a new silicon (Si) field emission devices (FE) fabrication process based on the potential of the HI-PS (Hydrogen Ion Porous Silicon) micromachining technique, which is a combination of hydrogen implantation and porous silicon. Devices with 2500 emitters (Si microtips), integrated and non-integrated to the anode, enclosed in an area of 2.8 x 2.8 mm² (3.2 x 10\'POT.4\' tips/cm²), were obtained from the proposed technique. The fabricated Si microtips show 10 µm in height, with apex diameter of about 150 nm. The separation distance between emitters (50 µm), considering the non-integrated devices design, was limited by the resolution of the lithographic mask applied. Microtips structural improvement process steps were proposed and applied in both anode-cathode design (integrated and non-integrated). As a result, a reduction in tip apex diameter to dimensions lower than 100 nm was verified. The integrated FE devices were obtained with an anode-cathode separation of about 12 µm, which distance was defined by lithographic mask dimensions, but not limited by the process applied. The outstanding advantages of the HI-PS technique in comparison with usual technologies for FE devices fabrication are the low complexity of the process proposed and the use of a single lithographic step to obtain a selfaligned and integrated anode-cathode system. A dedicated vacuum chamber, which allows the changing of the separation distance between non-integrated anodecathode structures without the need of removing the sample out the chamber, and three systems for electrical test, being one of them developed specifically for FE devices electrical characterization, were implemented. The electrical characterizations were performed by means of I-V, I-t and V-d curves, being the last one used to extract the macroscopic electrical field E, which was applied as comparison parameter between samples obtained from distinct structural improvement process and samples with emitters surface coated with Al. All samples characterized showed exponential-like behavior of current with the potential applied, as expected from theory proposed by Fowler-Nordheim (F-N). Devices with structural improvement or Al coating showed better emission characteristics (lower E value), according with the modified F-N model suggested in the literature for optimized surfaces. From the F-N plots, the distinct behavior of p type Si emitters was verified in comparison with different materials, establishing a relationship between the slope variations of the curve obtained and the electrons source of the Si. Based on the results obtained, the HI-PS technique is very promising to fabricate Si micromachined emitters for use in FE devices.

La miniaturisation des dispositifs de la microélectronique nécessite la mise au point de procédé de gravure toujours plus précis. Le sujet de cette thèse s’inscrit dans cette problématique, en effet un procédé de gravure séquentielle contrôlée à l’échelle nanométrique a été proposé pour pallier aux défauts inhérents à la gravure plasma directe. Ce procédé de gravure destiné dans notre cas à la gravure d’espaceurs en SiN, se décompose en deux étapes. La première étape est une implantation d’atome léger. L’implantation d’espèces chimiques légères telles que de l’Hydrogène ou de l’Hélium présente l’avantage de modifier la structure du matériau sans induire une pulvérisation dommageable pour le dispositif à graver. La couche modifiée par l’implantation est ensuite gravée de manière sélective vis-à-vis du matériau pristine via un plasma « downstream » ou plasma déporté.L’implantation d’hydrogène ayant principalement été étudiée au cours de ces travaux, différentes caractérisations visant à quantifier l’hydrogène implanté ainsi que l’épaisseur modifiée ont été réalisées. En effet, des mesures de réflectométrie des rayons X ont permis de déterminer l’épaisseur modifiée en fonction de la puissance d’autopolarisation ainsi que de la durée d’implantation. Des profils d’implant hydrogène sur du SiN ont également été effectués au travers de caractérisations électriques. Les profils de densité de charge obtenus ont été comparés à des profils de liaisons Si-H et N-H obtenus à partir de mesures spectroscopiques infra-rouge en réflexion multiple, et ces mesures ont également été comparées à des profils de spectrométrie de masse à ionisation secondaire. Ces profils permettent de quantifier l’hydrogène implanté en fonction de la profondeur, et ont également fournis des informations vis-à-vis de l’influence du rayonnement UV et de la configuration chimique du matériau implanté. Une présence significative d’oxyde à la surface du matériau implanté a également été observée par le biais de mesures spectroscopique de photoélectrons X.L’étape de retrait a principalement été étudiée via des mesures ellipsométriques cinétiques in situ, et des mesures spectroscopique de photoélectrons X pour différentes conditions de température, et pour différents mélanges chimiques. Les mesures ellipsométriques ont permis d’observer la formation de sels durant la gravure, alors que les analyses spectroscopiques de photoélectrons X ont montré que la surface du matériau été désoxydée par le plasma de retrait, parallèlement une quantité importante de fluor a été mesurée à la surface du matériau.Les études réalisées sur les étapes d’implantation et de retrait ont permis de graver de manière satisfaisante des échantillons patternés dans les conditions adéquates. / The miniaturization of microelectronics devices requires the development of ever more accurate etching processes. The subject of this thesis is part of this problematic: a controlled sequential etching process at the nanoscale has been developed to overcome the inherent defects of direct plasma etching. This etching process intended in our case for the etching for SiN spacers, is divided in two steps. The first step is a light atom implantation. The implantation of light chemical species such as Hydrogen or Helium has the advantage of modifying the structure of the material without inducing a damaging sputtering for the device to be etched. In the second step, the layer modified by the implantation is etched selectively regarding the pristine material via a remote plasma.Hydrogen implantation was mainly studied during this work: different characterizations to quantify the implanted hydrogen as well as the modified thickness were carried out. X-ray reflectometry measurements were used to determine the modified thickness as a function of the self-polarization power and the duration of implantation. Hydrogen implant profiles on SiN were also carried out through electrical characterizations. The charge density profiles observed were compared to Si-H and N-H bond profiles obtained from infrared spectroscopic measurements in multiple reflections. These measurements were also compared to secondary ionization mass spectrometry profiles. These profiles make it possible to quantify implanted hydrogen as a function of depth, and have also provided information regarding the influence of UV radiation and the chemical configuration of the implanted material. A significant presence of oxide on the surface of the implanted material has also been observed through X-ray photoelectron spectroscopic measurements.The removal step was mainly studied via kinetic ellipsometric in situ measurements and X-ray photoelectron spectroscopic measurements for different temperature conditions and for different chemical mixtures. The ellipsometric measurements made it possible to observe the formation of salts during etching, whereas the X-ray photoelectron spectroscopic analysis showed that the surface of the material was deoxidized by the remote plasma, while a large quantity of fluorine was measured at the same time on the material surface. The studies carried out on the implantation and removal steps made it possible to succesfully etch patterned samples under the appropriate conditions.

Um novo processo de fabricação de dispositivos de emissão de campo (FE) em silício (Si) é apresentado nesta tese, baseado na potencialidade de utilização da técnica de microusinagem denominada HI-PS (Hydrogen Ion Porous Silicon), que trata da combinação entre processos de implantação de hidrogênio e silício poroso. Por meio do procedimento proposto, foram obtidos dispositivos com 2500 emissores (micropontas de Si) integrados e não integrados ao anodo e contidos em uma área de 2,8 x 2,8 mm² (3,2.10\'POT.4\' pontas/cm²). As micropontas de Si fabricadas apresentaram altura de 10 µm, com diâmetro do ápice em torno de 150 nm. A separação entre os emissores (50 µm), na configuração não integrada dos dispositivos, foi limitada pela resolução da máscara litográfica utilizada. Foram propostas etapas de otimização estrutural das micropontas após sua formação, e aplicadas tanto na configuração do sistema anodo-catodo integrado como não integrado. Como resultado destas etapas, constatou-se a redução do ápice das microestruturas para dimensões inferiores a 100 nm. Os dispositivos FE integrados foram obtidos com uma distância de separação entre o anodo e o catodo de aproximadamente 12 µm, distância definida pelas dimensões da máscara litográfica, porém não limitada pelo processo aplicado. Destacam-se, entre as vantagens da utilização da técnica HI-PS em relação às tecnologias usuais de manufatura dos dispositivos FE, a baixa complexidade do processo proposto e a utilização de apenas uma etapa litográfica para obtenção do sistema anodo-catodo integrado e auto alinhado. Para efetuar as caracterizações dos dispositivos, foram implementados uma câmara de vácuo específica, que permite alterar a distância entre as estruturas do anodo e do catodo não integradas, sem a necessidade de se retirar a amostra da câmara, e três sistemas para ensaios elétricos, sendo um destes sistemas desenvolvido especificamente para caracterização elétrica de dispositivos FE. As caracterizações elétricas foram efetuadas por meio de curvas I-V, I-t e V-d, sendo esta última utilizada para extrair o campo elétrico macroscópico E, que foi utilizado como parâmetro de comparação entre amostras submetidas a diferentes processos de otimização estrutural e de recobrimento superficial dos emissores por Al. Todas as amostras caracterizadas apresentaram variação de corrente exponencial com o potencial aplicado, de acordo com o esperado pela teoria proposta por Fowler-Nordheim (F-N). Dispositivos com otimização estrutural ou deposição de Al apresentaram melhores características de emissão (menor valor de E), de acordo com o aprimoramento do modelo de F-N sugerido na literatura para superfícies otimizadas. Constatou-se, pelos gráficos de F-N, o comportamento diferenciado dos emissores de Si tipo p em comparação com outros materiais, estabelecendo uma relação entre as variações da inclinação da curva traçada às distintas fontes de elétrons do Si. Frente aos resultados obtidos, conclui-se que a técnica Hi-PS é altamente promissora para fabricação de emissores microusinados em Si para aplicações em dispositivos FE. / This thesis presents a new silicon (Si) field emission devices (FE) fabrication process based on the potential of the HI-PS (Hydrogen Ion Porous Silicon) micromachining technique, which is a combination of hydrogen implantation and porous silicon. Devices with 2500 emitters (Si microtips), integrated and non-integrated to the anode, enclosed in an area of 2.8 x 2.8 mm² (3.2 x 10\'POT.4\' tips/cm²), were obtained from the proposed technique. The fabricated Si microtips show 10 µm in height, with apex diameter of about 150 nm. The separation distance between emitters (50 µm), considering the non-integrated devices design, was limited by the resolution of the lithographic mask applied. Microtips structural improvement process steps were proposed and applied in both anode-cathode design (integrated and non-integrated). As a result, a reduction in tip apex diameter to dimensions lower than 100 nm was verified. The integrated FE devices were obtained with an anode-cathode separation of about 12 µm, which distance was defined by lithographic mask dimensions, but not limited by the process applied. The outstanding advantages of the HI-PS technique in comparison with usual technologies for FE devices fabrication are the low complexity of the process proposed and the use of a single lithographic step to obtain a selfaligned and integrated anode-cathode system. A dedicated vacuum chamber, which allows the changing of the separation distance between non-integrated anodecathode structures without the need of removing the sample out the chamber, and three systems for electrical test, being one of them developed specifically for FE devices electrical characterization, were implemented. The electrical characterizations were performed by means of I-V, I-t and V-d curves, being the last one used to extract the macroscopic electrical field E, which was applied as comparison parameter between samples obtained from distinct structural improvement process and samples with emitters surface coated with Al. All samples characterized showed exponential-like behavior of current with the potential applied, as expected from theory proposed by Fowler-Nordheim (F-N). Devices with structural improvement or Al coating showed better emission characteristics (lower E value), according with the modified F-N model suggested in the literature for optimized surfaces. From the F-N plots, the distinct behavior of p type Si emitters was verified in comparison with different materials, establishing a relationship between the slope variations of the curve obtained and the electrons source of the Si. Based on the results obtained, the HI-PS technique is very promising to fabricate Si micromachined emitters for use in FE devices.

No description available.

In this work, we have developed two different fabrication processes for relaxed Si₁₋xGex-on-insulator (SGOI) substrates: (1) SGOI fabrication by etch-back approach, and (2) by "smart-cut" approach utilizing hydrogen implantation. Etch-back approach produces SGOI substrate with less defects in SiGe film, but the SiGe film uniformity is inferior. "Smart-cut" approach has better control on the SiGe film thickness and uniformity, and is applicable to wider Ge content range of the SiGe film. We have also fabricated strained-Si n-MOSFET’s on SGOI substrates, in which epitaxial regrowth was used to produce the surface strained Si layer on relaxed SGOI substrate, followed by large-area n-MOSFET’s fabrication on this structure. The measured electron mobility shows significant enhancement (1.7 times) over both the universal mobility and that of co-processed bulk-Si MOSFET’s. This SGOI process has a low thermal budget and thus is compatible with a wide range of Ge contents in Si₁₋xGex layer. / Singapore-MIT Alliance (SMA)

Orientador: Prof. Dr. Michel Oliveira da Silva Dantas / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2016. / Sensores de vacuo sao amplamente utilizados tanto no ambito industrial como no da pesquisa cientifica, pois possuem aplicacoes em diversas tecnicas de fabricacao e de analise, como a microscopia eletronica de varredura (MEV), a litografia por feixe de eletrons, e a espectrometria de massa, entre outras. Dentre os diversos tipos de sensores de vacuo destacam-se os baseados em efeito de campo (FE - Field Emission Device), que sao dispositivos que emitem eletrons em vacuo na presenca de um elevado campo eletrico. A literatura destaca diversas vantagens destes dispositivos: operacao em temperatura ambiente, reducao de consumo de potencia e tensao de operacao, obtencao de altas densidades de correntes em areas reduzidas, e rapido tempo de resposta. Existem diversas tecnicas de microfabricacao que podem ser utilizadas para obtencao de dispositivos FE, destacando-se a tecnica HI-PS (gHydrogen Implantation . Porous Siliconh), que proporciona baixa complexidade e custo. No entanto, para obtencao de FEs com sistema anodo-catodo integrado, a tecnica HI-PS apresenta algumas limitacoes, como o elevado numero de etapas de processo, a necessidade de elevada temperatura e tempo de oxidacao, e principalmente a isolacao eletrica deficiente entre as estruturas do anodo e do catodo, propiciando a existencia de correntes de fuga pelo gcorpoh do dispositivo. Frente a estes problemas, este trabalho apresenta estrategias estudadas para aprimorar a tecnica HI-PS de microfabricacao de dispositivos de emissao de campo integrados. Visando a reducao do numero de etapas de processo e a eliminacao de defeitos, inicialmente, foi estudada a utilizacao de fotorresiste como mascara a implantacao ionica de hidrogenio. Esta estrategia se mostrou viavel, resultando na formacao seletiva de silicio poroso e na obtencao de micropontas (catodos) com altura em torno de 10 ¿Êm e diametro dos apices em torno de dezenas de nanometro, dimensoes estas atestadas por MEV. Tambem foi pesquisada a utilizacao de fotorresiste como camada dieletrica, que se mostrou inviavel para a aplicacao proposta devido aos valores de correntes de fuga relativamente elevados. Para melhorar a isolacao eletrica entre as estruturas do anodo e do catodo, a estrategia pesquisada foi a utilizacao de oxido de silicio poroso (Ox-PS) como camada dieletrica entre as referidas estruturas. Para obtencao do Ox-PS, foram estudados diferentes parametros de oxidacao, como temperatura, tempo de processo, gradiente de temperatura de oxidacao (pre-oxidacao), e processo de recozimento termico pos-oxidacao em ambiente Forming Gas. Para as caracterizacoes morfologicas do Ox-PS, foram analisados, por meio de microscopia otica, parametros como espessura, estabilidade estrutural, taxa de corrosao e oxidacao total da camada PS, sendo este ultimo realizado atraves da tecnica Fourier Transform Infrared Spectroscopy (FTIR). Para a caracterizacao eletrica da corrente de fuga, foram confeccionados dispositivos MOS, caracterizados eletricamente por aparato constituido por um analisador de parametros semicondutores. O Ox-PS obtido com T = 1000 ¿C, t = 1 h, e com recozimento termico pos-oxidacao em ambiente Forming Gas apresentou significativa reducao da corrente de fuga (de 30 nA para 0,125 nA), comprovando, deste modo, sua potencialidade para a aplicacao proposta. Ja na fabricacao do FE integrado, o Ox-PS obtido nestas condicoes apresentou elevada instabilidade estrutural, gerando a necessidade de implementar processos de pre-oxidacao para obtencao da estrutura anodo-catodo integrada. Atraves dos parametros adequados, foi finalmente comprovada a viabilidade da otimizacao da tecnica HI-PS atraves das estrategias estudadas, possibilitando a fabricacao do dispositivo FE integrado contendo micropontas de alturas de aproximadamente 10 micrometros e apices da ordem de dezenas de nanometros circundadas pela estrutura do anodo com distancias de separacao de aproximadamente 20 micrometros. Com a otimizacao dos processos de fabricacao, almeja-se futuramente implementar o dispositivo FE integrado obtido por HI-PS no desenvolvimento de sensores compactos e de baixo custo e complexidade de fabricacao. / Vacuum sensors are widely used in industry and in scientific research, because they can be applied in several fabrication and analysis techniques, such as Scanning Electron Microscopy (SEM), electron beam lithography and mass spectrometry, for example. Among the large number of vacuum sensors, we can highlight the Field Emission Devices (FE), which are devices that emit electrons in vacuum environment when submitted to a high electric field. The literature reports several advantages of these devices: operation at room temperature, low power consumption, high current densities in small areas, and fast response times. Several microfabrication techniques allow obtaining FE devices, including the HI-PS (Hydrogen Implantation ¿ Porous Silicon) technique, which is remarkable due to its low complexity and cost. However, HI-PS presents some limitations when applied to obtain FE with integrated anode-cathode system: high number of process steps, high temperature and oxidation times, and mainly the poor electrical insulation between anode-cathode structures, which results in leakage currents through the bulk of these devices. In this context, this work shows strategies to improve the HI-PS technique for microfabrication of integrated FE devices. First, we use photoresist as mask for hydrogen ion implantation aiming at defects elimination and reduction of process steps. This strategy resulted in the selective formation of porous silicon and in obtaining microtips (cathodes) with 10 ìm height and apex around tens of nanometers, as verified by Scanning Electron Microscopy (SEM). In addition, photoresist was tested as dielectric between anodecathode structures, but the high leakage current measured hindered the use of this material for the proposed application. The main strategy researched to improve the electrical insulation between anode-cathode structures was the use of oxidized porous silicon (Ox-PS) as dielectric. To obtain Ox-PS, we studied oxidation parameters such as temperature, time, pre-oxidation, and post-oxidation annealing. Optical Microscopy and Fourier Transform Infrared Spectroscopy (FTIR) were applied to analyze morphological aspects such as thickness, stability, etch rates and full oxidation of PS layers. A semiconductor parameter analyzer was used to characterize the leakage current from fabricated MOS devices. The Ox-PS obtained with T = 1000 °C, t = 1 h, and post-oxidation annealing in Forming Gas environment showed remarkable decrease of leakage current in comparison to the other oxidation conditions (from 30 nA to 0,125 nA), which demonstrates potentiality for the proposed application. Additionally, a pre-oxidation process was introduced to improve structural stability of Ox-PS layers. After this implementation, the optimization viability of HI-PS technique was finally proved, allowing obtaining an integrated FE device with microtips with 10 micrometers height and apex about tens of nanometers surrounded by the anode structure. The separation distance between anode-cathode structures was about 20 micrometers. With the optimization of fabrication process, we intend to implement hereafter the integrated FE device obtained by HI-PS technique in the development of compact sensors with low cost and low fabrication complexity.

Le procédé Smart CutTM, utilisé pour le transfert de films minces sur substrat est basé sur la fissuration du silicium. La propagation des fissures est initiée à partir de défauts bidimensionnels induits par implantation d'hydrogène, les « H-platelets ». Des études précédentes ont montré que la fissuration du Si peut également être obtenue à partir de défauts nommés « He-plates » qui ont la particularité d'avoir un diamètre dix fois supérieur. L'objectif de ce travail était d'étudier la formation de ces défauts et leur évolution sous flux d'hydrogène jusqu'à la propagation des fissures. Dans une première partie, la formation des « He-plates » a été étudiée pour différentes orientations de substrats et discutée par rapport à la contrainte compressive bi-axiale induite par l'implantation. Les résultats montrent que les mécanismes qui gouvernent la formation des « He-plates » sont les mêmes que pour les « H-platelets ». Dans une seconde partie, l'évolution des « He-plates » en présence d'H a été étudiée en utilisant une approche expérimentale originale qui couple implantations d'hydrogène et observations par microscopie électronique en transmission. Les expériences montrent que la croissance des « He-plates » est gouvernée par la diffusion de l'hydrogène qui dépend de la température et du taux d'endommagement. Enfin, leur croissance est décrite à l'aide d'un modèle cinétique et, leur coalescence a été analysée en relation avec un modèle élastique. La propagation rectiligne de fissures à partir de ces précurseurs offre des perspectives intéressantes pour une utilisation industrielle. / The Smart CutTM process, used in the transfer of thin films on substrates is based on the cracking of silicon. The crack propagation is initiated from bi-dimensional defects induced by H-implantation, the H-platelets. Previous studies showed that the propagation of cracks in Si can also be triggered from defects named He-plates which have the particular feature of having a diameter ten times larger. The aim of this work was to study the formation of these defects and their evolution until the crack propagation under H supply.In a first part, the formation of He-plates was studied for different substrate orientations and discussed regarding the bi-axial compressive stress induced by implantation. Results show that the mechanisms that govern the He-plate formation are the same than for H-platelet formation. In a second part, the evolution of He-plates under H supply was studied by using an original experimental approach that combines H-implantation and transmission electron microscopy observations. Experiments show that the growth of He-plates is controlled by the diffusion of hydrogen which depends on temperature and damage rate. Finally, the growth is described by a kinetic model and their coalescence was analyzed with regard to an elastic model. The straight propagation of cracks from He-plates offers promising outlook for an industrial use.

La thèse porte sur l’étude de la cinétique de Smart Cut™ dans du silicium après implantation hydrogène, pour des températures de recuit comprises entre 500°C et 1300°C. Ainsi, la cinétique de séparation de couches (splitting) est caractérisée en considérant des recuits dans un four à moufle ainsi que des recuits laser. Sur la base de cette caractérisation, un modèle physique, basé sur le comportement de l’hydrogène implanté durant le recuit, est proposé. Le modèle s’appuie sur des caractérisations SIMS de l’évolution de la concentration d’hydrogène durant le recuit, ainsi que sur des simulations numériques. Le modèle propose une explication aux propriétés des films obtenus en fonction des conditions de recuit et mesurées par microscopie optique, AFM ainsi que par des mesures des énergies d’interfaces. Sur la base du modèle de splitting obtenu, deux procédés de fabrication de films de silicium sont proposés pour l’élaboration de matériaux de silicium sur saphir et verre par recuit laser ainsi que pour l’élaboration de feuilles de silicium monocristallin par épitaxie en phase liquide sur substrat silicium implanté. L’étude de premier procédé prouve pour la première fois la possibilité d’appliquer le procédé Smart Cut™ sur des substrats de silicium implanté. Les films ainsi obtenus présentent des grandes surfaces de transfert (wafer de 200 mm), ce qui présente un grand intérêt industriel. L’étude propose différentes caractérisations des films obtenus (AFM, profilométrie optique, mesure 4 pointe). Le deuxième procédé est démontré en utilisant des bancs d’épitaxie en phase liquide de silicium (température supérieure à 1410°C) afin d’effectuer des dépôts sur des substrats de silicium implantés. Les films obtenus montrent un grand degré de croissance épitaxiale (jusqu’à 90% du film déposé mesuré par EBSD) et présentent une épaisseur aussi faible que 100 µm. D’autre part, le détachement par Smart Cut™ des films ainsi déposés est démontré. / At first, the thesis studies the kinetics of Smart Cut™ in silicon implanted with hydrogen ions for annealing temperature in the range 500°C-1300°C. The kinetics is characterized by using a specially-dedicated furnace and by considering laser annealing. Based on the related characterization and observations, a physical model is established based on the behavior of implanted hydrogen during annealing. The model is strengthened by SIMS characterization focused on the evolution of hydrogen during annealing and on numerical calculations. Additionally, the model proposes an explanation for the properties of the obtained films as a function of the annealing conditions, based on optical microscope and AFM observations and bonding energy characterization. Based on this splitting model, two innovative processes for fabrication of silicon films are proposed. The first process allows to produce films of silicon on sapphire and films of silicon on glass by considering a laser annealing. The second produces foils of monocrystalline silicon by liquid phase epitaxial growth on implanted silicon substrate. The study of the first process proves for the first time the possibility to apply the Smart Cut™ for substrates of implanted silicon. The resulting films present large surface of transferred films (up to 200 mm wafers), which is very interesting in an industrial perspective. The study proposes different characterization of the films obtained by this process (AFM, optical profilometry and 4 probe measurement). The second process is demonstrated by using a chamber of liquid phase epitaxial growth of silicon (deposition temperature superior to 1410°C) in order to deposit liquid silicon on implanted silicon substrates. The obtained films show a high degree of epitaxial growth (up to 90% of the film as characterized by EBSD) and show a thickness as low as 100µm. Additionally the detachment by Smart Cut of the deposited films is demonstrated.

The effect of proton (H+) irradiation on uranium mononitride (UN) and UN compositefuel with 10 at.% ZrN (UN10at%ZrN) was examined. Protons of 2 MeV with fluences of1E17, 1E18, 1E19 and 1E20 ions/cm2 were accelerated towards the fabricated samples in orderto investigate the evolution of the micro-structure. Stopping and Range of Ions in Matter(SRIM) calculations were performed to determine the displacements per atom associatedwith the depth of the highest damage, for each fluence.X-Ray diffraction (XRD) was used in both samples to identify the chemical composition ofeach pellet, which revealed the low presence of oxygen. Based on scanning electron microscopy(SEM), deterioration of the samples surface was observed, as the proton fluence increased.The applied stress due to the irradiation, led to the cracking of the pellets at the highestfluences. Blisters and craters appear to surround the cracked region, which might originatefrom the significant levels of hydrogen implantation within the samples.From Electron backscatter diffraction (EBSD) analysis, the grain size of the UN10at%ZrNcomposite was found to be smaller than in UN, due to the nano-particle nature of the ZrNpowder. The latter technique was also used to observe the elevated irradiated regions, whichwere further investigated by atomic force microscopy (AFM). Nano-indentation detectedirradiation hardening for both samples in the irradiated regions. Focused ion beam (FIB)milling was applied to remove lamellas from the cracked regions in both UN and compositesamples in order to be analyzed by transmission electron microscopy (TEM). The latter mightreveals the formation of dislocation loops in the irradiated areas. / Effekten av protonbestrålning på urannitrid (UN) och UN-kompositbränsle med 10 at.% ZrN (UN10at%ZrN) undersöktes. Protoner på 2 MeV med total dos på 1E17, 1E18, 1E19 och 1E20 joner/cm2 accelererades mot de tillverkade proverna för att undersöka utvecklingen av mikrostrukturen under bestrålning. SRIM-beräkningar (Stopping and Range of Ions in Matter) utfördes för att bestämma profilen på skadan och jonimplanteringen i förhållande till djupet, för varje dosnivå.  Röntgendiffraktion (XRD) användes på båda proverna för att identifiera den kemiska sammansättningen av varje kuts, vilket visade att syrehalten var låg. Med hjälp av svepelektronmikroskopi (SEM) observerades en försämring av provernas yta när protonflödet ökade. Den resulterande mekaniska spänningen överskred provets brottstyrka på djupet, eftersom nitriderna inte är så duktila, vilket ledde till sprickbildning i proverna som utsattes för de högsta doserna. Blåsor och kratrar omger det spruckna området, vilket beror på betydande väteimplantering i provet.  Genom electron backscatter diffraction analys (EBSD) konstaterades att kornstorleken hos UN10at%ZrN-kompositen var mindre än hos UN, på grund av ZrN-pulvrets nanopartikelnatur. Den sistnämnda tekniken användes för att observera de högt bestrålade områdena, som undersöktes ytterligare med Atomic force microscopy (AFM). Genom nano-indientation upptäcktes bestrålningshärdning för båda proverna i de bestrålade områdena. Fräsning med en fokuserad jonstråle (FIB) användes för att avlägsna lameller från de spruckna områdena i både UN- och kompositprovet för att kunna analyseras med transmission electron microscopy (TEM). Det senare visade att det bildades dislokationer i de bestrålade områdena.