Ce travail a permis dans un premier temps, l’élaboration de composites semi-conducteurs à base de nanoobjetspossédant des caractéristiques électrochimiques spécifiques en fonction du type d’inclusion (siliciumdopé N ou dopé P et oxydes métalliques, ZnO, SnO2, NiO). Ces composites ont permis d’obtenir avec succèsdes encres de sérigraphie présentant un comportement électrique semi-conducteur qui ont servi à laréalisation d’électrodes par dépôt sur divers supports et notamment des films plastiques souples. Lamodification chimique des supports réalisés a été étudiée en vue de pouvoir utiliser ce type de matériaucomme transducteurs électrochimiques en les intégrant dans des dispositifs de types capteurs et biocapteurs.Dans un second temps, un composite photostructurable conducteur a également été développé en se basantsur la technologie SU-8, et en y incluant des particules de graphite ou des nanoparticules de carbone noir.Ce photocomposite a été par la suite fonctionnalisé avec succès par des dérivés diazonium, tel que lebromobenzène diazonium ou le nitrobenzène diazonium dont les greffages ont été suivis par spectroscopied’impédance. Enfin, le greffage d’oligonucléotides via la chimie des sels d’aryldiazonium a également étéeffectué avec succès et utilisé pour la détection de séquences cibles à des concentrations de 100 pM à 200nM. / The first part of this study report the development of semiconducting composites consisting ofsemiconducting nano-objects (N doped, P doped silicon or metals oxides, ZnO, SnO2, NiO) held together inan insulating polymeric matrix and exhibiting typical semiconductor impedance signals according to thecharge used and with clear differentiation between the two fundamental type of semiconductor, n-type and ptype.This new composites have been used as screen-printing ink. Electrodes on various substrates (PVC,glass) have been successfully prepared following this cost-effective method. Surface functionalization ofthese electrodes by chemicals compounds and biomolecules was studied using impedance spectroscopy andchemiluminescent detection in order to assess their integration as electrochemical transducers in sensorsand biosensors microdevices.The second part of this work consisted in photopatternable conductive composite elaboration using a simpleand straightforward route based on SU-8 epoxy-based negative photoresist matrix mixed with carbon filler.The electrodes, obtained by the classical photolithography method, and after an electrochemical pretreatment,exhibited very good electrochemical behaviors, opening the path to various electrochemicaldetections and grafting possibilities. Finally, the direct electrografting of biomolecules was demonstratedusing aniline modified oligonucleotide probes. The grafted probes were shown to be available for targethybridization and the material compatible with a chemiluminescent detection of the interactions between theimmobilized single stranded DNA and its complementary sequence in a 100 pM to 200 nM range.

<p>Semiconductor wafer bonding has been a subject of interestfor many years and a wide variety of wafer bonding techniqueshave been reported in literature. In adhesive wafer bondingorganic and inorganic adhesives are used as intermediatebonding material. The main advantages of adhesive wafer bondingare the relatively low bonding temperatures, the lack of needfor an electric voltage or current, the compatibility withstandard CMOS wafers and the ability to join practically anykind of wafer materials. Adhesive wafer bonding requires nospecial wafer surface treatmentssuch as planarisation.Structures and particles at the wafer surfaces can be toleratedand compensated for some extent by the adhesive material.Adhesive wafer bonding is a comparably simple, robust andlowcost bonding process. In this thesis, adhesive wafer bondingtechniques with different polymer adhesives have beendeveloped. The relevant bonding parameters needed to achievehigh quality and high yield wafer bonds have been investigated.A selective adhesive wafer bonding process has also beendeveloped that allows localised bonding on lithographicallydefined wafer areas.</p><p>Adhesive wafer bonding has been utilised in variousapplication areas. A novel CMOS compatible film, device andmembrane transfer bonding technique has been developed. Thistechnique allows the integration of standard CMOS circuits withthin film transducers that can consist of practically any typeof crystalline or noncrystalline high performance material(e.g. monocrystalline silicon, gallium arsenide,indium-phosphide, etc.). The transferred transducers or filmscan be thinner than 0.3 µm. The feature sizes of thetransferred transducers can be below 1.5 µm and theelectrical via contacts between the transducers and the newsubstrate wafer can be as small as 3x3 µm2. Teststructures for temperature coefficient of resistancemeasurements of semiconductor materials have been fabricatedusing device transfer bonding. Arrays of polycrystallinesilicon bolometers for use in uncooled infrared focal planearrays have been fabricated using membrane transfer bonding.The bolometers consist of free-hanging membrane structures thatare thermally isolated from the substrate wafer. Thepolycrystalline silicon bolometers are fabricated on asacrificial substrate wafer. Subsequently, they are transferredand integrated on a new substrate wafer using membrane transferbonding. With the same membrane transfer bonding technique,arrays of torsional monocrystalline silicon micromirrors havebeen fabricated. The mirrors have a size of 16x16 µm2 anda thickness of 0.34 µm. The advantages of micromirrorsmade of monocrystalline silicon are their flatness, uniformityand mechanical stability. Selective adhesive wafer bonding hasbeen used to fabricate very shallow cavities that can beutilised in packaging and component protection applications. Anew concept is proposed that allows hermetic sealing ofcavities fabricated using adhesive wafer bonding. Furthermore,microfluidic devices, channels and passive valves for use inmicro total analysis systems are presented.</p><p>Adhesive wafer bonding is a generic CMOS compatible bondingtechnique that can be used for fabrication and integration ofvarious microsystems such as infrared focal plane arrays,spatial light modulators, microoptical systems, laser systems,MEMS, RF-MEMS and stacking of active electronic films forthree-dimensional high-density integration of electroniccircuits. Adhesive wafer bonding can also be used forfabrication of microcavities in packaging applications, forwafer-level stacking of integrated circuit chips (e.g. memorychips) and for fabrication of microfluidic systems.</p>

Semiconductor wafer bonding has been a subject of interestfor many years and a wide variety of wafer bonding techniqueshave been reported in literature. In adhesive wafer bondingorganic and inorganic adhesives are used as intermediatebonding material. The main advantages of adhesive wafer bondingare the relatively low bonding temperatures, the lack of needfor an electric voltage or current, the compatibility withstandard CMOS wafers and the ability to join practically anykind of wafer materials. Adhesive wafer bonding requires nospecial wafer surface treatmentssuch as planarisation.Structures and particles at the wafer surfaces can be toleratedand compensated for some extent by the adhesive material.Adhesive wafer bonding is a comparably simple, robust andlowcost bonding process. In this thesis, adhesive wafer bondingtechniques with different polymer adhesives have beendeveloped. The relevant bonding parameters needed to achievehigh quality and high yield wafer bonds have been investigated.A selective adhesive wafer bonding process has also beendeveloped that allows localised bonding on lithographicallydefined wafer areas. Adhesive wafer bonding has been utilised in variousapplication areas. A novel CMOS compatible film, device andmembrane transfer bonding technique has been developed. Thistechnique allows the integration of standard CMOS circuits withthin film transducers that can consist of practically any typeof crystalline or noncrystalline high performance material(e.g. monocrystalline silicon, gallium arsenide,indium-phosphide, etc.). The transferred transducers or filmscan be thinner than 0.3 µm. The feature sizes of thetransferred transducers can be below 1.5 µm and theelectrical via contacts between the transducers and the newsubstrate wafer can be as small as 3x3 µm2. Teststructures for temperature coefficient of resistancemeasurements of semiconductor materials have been fabricatedusing device transfer bonding. Arrays of polycrystallinesilicon bolometers for use in uncooled infrared focal planearrays have been fabricated using membrane transfer bonding.The bolometers consist of free-hanging membrane structures thatare thermally isolated from the substrate wafer. Thepolycrystalline silicon bolometers are fabricated on asacrificial substrate wafer. Subsequently, they are transferredand integrated on a new substrate wafer using membrane transferbonding. With the same membrane transfer bonding technique,arrays of torsional monocrystalline silicon micromirrors havebeen fabricated. The mirrors have a size of 16x16 µm2 anda thickness of 0.34 µm. The advantages of micromirrorsmade of monocrystalline silicon are their flatness, uniformityand mechanical stability. Selective adhesive wafer bonding hasbeen used to fabricate very shallow cavities that can beutilised in packaging and component protection applications. Anew concept is proposed that allows hermetic sealing ofcavities fabricated using adhesive wafer bonding. Furthermore,microfluidic devices, channels and passive valves for use inmicro total analysis systems are presented. Adhesive wafer bonding is a generic CMOS compatible bondingtechnique that can be used for fabrication and integration ofvarious microsystems such as infrared focal plane arrays,spatial light modulators, microoptical systems, laser systems,MEMS, RF-MEMS and stacking of active electronic films forthree-dimensional high-density integration of electroniccircuits. Adhesive wafer bonding can also be used forfabrication of microcavities in packaging applications, forwafer-level stacking of integrated circuit chips (e.g. memorychips) and for fabrication of microfluidic systems.

Dans le procédé d'élaboration d'un transistor, la définition des motifs de grilles est une des étapes les plus dures à contrôler. Avec la miniaturisation des dispositifs, les spécifications définies pour la structuration des transistors se sont resserrées jusqu'à l'échelle du nanomètre. Ainsi, le Contrôle Dimensionnel(CD) et la rugosité de bord des lignes (LWR) sont devenus les paramètres les plus importantes à contrôler. Précédemment, pour atteindre les objectifs définis pour les précédentes technologies CMOS, des traitements post-lithographiques tels que les traitements plasma à base d’HBr ont été introduits pour améliorer la résistance des résines aux plasmas de gravure et minimiser la rugosité des motifs de résine avant leur transfert dans l’empilement de grille. Cependant, ces méthodes conventionnelles ne sont plus satisfaisantes pour atteindre les spécifications des nœuds avancés 14FDSOI, qui font intervenir des schémas complexes d’intégration de motifs. Dans ces travaux, les limitations des traitements plasma HBr pour réaliser des motifs de grille bidimensionnels comme définis par les règles de dessin ont été mises en évidence. . En effet, il s’avère que les traitements par plasma HBr sont responsables d'un déplacement local du motif de grille, qui entraine sur le produit final une perte de rendement. Des résultats préliminaires montrent que le retrait de cette étape de traitement améliore le phénomène de décalage des grilles, au détriment de la rugosité des motifs de résines. En effet, les résines non traités par plasma subissent d’importantes contraintes lors de l’ étape de gravure SiARC en plasma fluorocarbonnés, ce qui génère une nette augmentation de la rugosité de la résine qui se transfère par la suite dans les couches actives du dispositif. Dans cette thèse, j’ai étudié les mécanismes de dégradation des résines dans des plasmas fluorocarbonés. Cette compréhension a abouti au développement d’une nouvelle chimie de gravure plasma de la couche de SiARC qui limite la dégradation des résines. De plus, j’ai évalué comment le procédé complet de gravure de grille métallique peut être amélioré pour éliminer la rugosité et la déformation des motifs en travaillant sur chacune des étapes impliquées. Le but de cette étude est d’identifier les étapes de gravure ayant un rôle dans la rugosité finale de la grille. Mes travaux montrent que l'ajout des étapes de nitruration limite la dégradation du profil de grille et de la rugosité des flancs. Au contraire, la microstructure du film de TiN ainsi que les procédés de gravure de grille métal n'ont pas d'impact sur la rugosité finale du dispositif. Le transfert du motif de grille lors des étapes de gravure du masque dur reste toujours le principal contributeur de la rugosité finale de grille. / In a transistor manufacturing process, patterning is one of the hardest stages to control. Along with downscaling, the specifications for a transistor manufacturing have tightened up to the nanometer scale. Extreme metrology and process control are required and Critical Dimension Uniformity (CDU) and Line Width Roughness (LWR) have become two of the most important parameters to control.So far, to meet the requirements of the latest CMOS technologies, post-lithography treatments such as plasma cure treatments have been introduced to increase photo-resist stability and to improve LWR prior to pattern transfer. However, conventional post-lithography treatments are no more efficient to address the specifications of14nm gate patterning where more complicated designs are involved.In this work, we have studied limitations of cure pretreatments in 2D gate integrations. In fact, the HBr plasma post-lithography treatment was identified as being responsible of a local pattern shifting that result in a loss of the device’s electrical performance. Preliminary results show that, cure step removal helps to control pattern shifting but to the detriment of the LWR. Indeed, if no cure treatment is introduced in the gate patterning process flow, photoresist patterns undergo severe stress during the subsequent Si-ARC plasma etching in fluorocarbon based plasmas. In this work, the mechanisms that drive such resist degradation in fluorocarbon plasmas have been studied and improved SiARC etch process condition shave been proposed. Besides, we evaluate how the state-of-art gate etch process can be improved, by investigating the impact of each plasma etching step involved in the high-K metal gate patterning on both LWR and gate shifting. The goal of this study is to determine if the TiN metal gate roughness can be modified by changing the gate etch process conditions. Our research reveals that addition of N2 flash steps prevents from gate profile degradation and sidewall roughening. In revenge, the TiN microstructure as well as the HKMG etch process has no impact on the gate final roughness. The hard mask patterning process remains the main contributor for gate roughening.

A chaque nouvelle étape franchie dans la réduction des dimensions des dispositifs en microélectronique, de nouvelles problématiques sont soulevées. Parmi elles, la fluctuation de la longueur de la grille des transistors, aussi appelée rugosité de bord de ligne (LWR, pour “Line Width Roughness”), constitue l'une des principales sources de variabilité. Afin d'assurer le bon fonctionnement des transistors, le LWR doit être inférieur à 2 nm pour les futurs noeuds technologiques. Dans ce contexte, la caractérisation précise de la rugosité à l'échelle nanométrique est essentielle mais se heurte aux limitations des équipements de métrologie. En effet, à ces dimensions, le bruit de mesure des équipements ne peut être ignoré. Afin de pallier à ce problème, un protocole permettant de s'affranchir du niveau de bruit des équipements de métrologie a été développé dans la première partie de cette thèse. Il s'appuie sur l'utilisation de la densité spectrale de puissance de la rugosité, basée sur une fonction d'autocorrélation de type "fractal auto-affine". Un bruit "blanc" a été inclus dans le modèle théorique, permettant l'ajustement des données expérimentales. La seconde problématique concerne la rugosité élevée des motifs des résines 193 nm qui est transférée dans la grille lors des étapes successives de gravure. Pour résoudre cette difficulté, des traitements plasma sur résines ont été envisagés dans la seconde partie de cette étude. Des analyses physico-chimiques des résines exposées aux traitements plasma nous ont permis de montrer que les UV émis par les plasmas lissent considérablement les flancs des résines. En contrepartie, la formation d'une couche "dure" autour des motifs avec certains plasmas (HBr et Ar) contribue à leur dégradation. De nouvelles stratégies ont également été examinées. Les traitements plasma ont été combinés à des recuits thermiques dans le but d'additionner leurs avantages. Finalement, un plasma de H2 semble être prometteur puisqu'il ne génère pas de couche superficielle sur les motifs de résine, et l'action des UV réduit considérablement la rugosité. En combinant ce traitement avec un recuit thermique, il est possible d'atteindre des rugosités de 2.4 nm dans la grille finale. / With the constant decrease of dimensions in microelectronic devices, new problemes are raised. One of them is the variation of the transistor gate length, also called "Line Width Roughness" (LWR), which constitutes one of the most important sources of device variability. Regarding the future technological nodes, the LWR becomes a serious issue and should be reduced down to 2 nm. In this context, the acurate characterization of the LWR at the nanometric scale is essential but faces metrology tool limitations. At this scale, the equipment noise level can not be ignored.In order to compensate for this problem, a protocol allowing to get rid of the metrology equipment noise has been developped. It relies on the use of the discrete power spectral density, based on a "self affine fracal" autocorrelation function type. A "white" noise has been incorporated to the theoretical model, allowing the fitting of experimental data.The second issue concerns the significant LWR of the photoresist patterns printed by 193nm lithography, known to be partially transferred into the gate stack during the subsequent plasma etching steps. In order to solve this difficulty, plasma treatments have been applied to photoresists. Physico-chemical analysis of resists exposed to different plasma allowed us to observe that the UV emitted by the plama significantly smooth the resist sidewalls. On the other hand, the formation of a "stiff" layer around the patterns with some of the used plasma (namely HBr and Ar) leads to a degradation of the sidewall. New strategies have also been examined. Plasma treatments were especially combined to annealing treatments in order to couple their advantages. Finally, the H2 plasma appears as the most promissing for that it does not generate any surface "stiff" layer on the resist patterns and the UV significantly smooth the roughness. Combining this treatment with an annealing, it is possible to reach roughnesses as low as 2.4 nm in the final gate.

Organické elektronické zariadenia sú vyvíjané ako vhodné riešenia senzorov pre bioelektroniku, a to najmä kvôli dobrej biokompatibilite organických polovodičov v nich použitých. Takzvané biosenzory dokážu premeniť elektrochemické procesy na elektronický signál. Matrica takýchto biosenzorov môže simultánne skenovať množstvo biologických vzoriek, alebo rôznych tkanív v živých systémoch. Aktívnou súčasťou zariadenia je organický elektrochemický tranzistor (OECT). V tejto práci je diskutovaný teoretický rámec fungovania takéhoto zariadenia, jeho elektrická charakterizácia, aplikácia v biosenzoroch na báze buniek, spôsoby výroby a aktuálnym stavom techniky v oblasti organickej elektroniky. Experimentálna časť obsahuje konkrétne výrobné postupy vývoja OECT zariadení, ktoré boli použité v našom laboratóriu. Hlavný dôraz sa kladie na schopnosť vyrobených zariadení detekovať reakciu a monitorovať stimuláciu elektrogenných buniek. Za týmto účelom boli vyvinuté matice mikroelektródových OECT zariadení založených na polovodivom polyméri PEDOT:PSS. Tieto boli vyrobené s využitím bežnými tlačiarenských techník (atramentová tlač a sieťotlač) spolu so štandardnými litografickými postupmi. Najnovšie nami vyvinuté zariadenia dosahujú najväčšieho zosílením signálu, g = 2,5 mS a časovú konštantu t = 0,15 s. Tieto zariadenia sú porovnateľné, často dokonca lepšie ako niektoré iné najmodernejšie a plne litograficky pripravené senzory.

Photopolymerization is a technique used to create surface structures or microobjects from a photoresist. This process is started by illuminating the sample with a light of proper wavelength absorbed by the resist. After exposure, the sample is processed according to the type of the photoresist – be it heating, treating with developer or just washing the unaffected monomer with some reagent. Focused femtosecond laser beam with double wavelength can be used in the process. Short pulse length with high photon density starts two-photon absorption localized in the vicinity of focal point. The method resolution is thus increased and details with 1/10 micrometer size can be created. Moreover, very short laser pulse decreases the heat affected zone and the risk of thermal initiation is minimized. Manufacturing of larger structures composed of tiny details with two-photon photopolymerization is time-demanding process. Therefore, we have complemented the optical setup with spatial light modulator (SLM), which splits the incoming laser beam into several beams with holograms dynamically generated by a computer. Polymerization can be thus performed by multiple foci simultaneously which can be used to create separated microparticles or periodical surface structures. Additional speed improvement of the process can be substitution of static configuration, requiring sample replacement after each exposition, with continuous setup using microfluidic channel steadily supplied with photoresist transported to the active region of the sample.

No description available.

This thesis presents the theory design and fabrication of a diffractive grating coupler. The first part of the design process is to choose the period of the grating coupler based on the desired coupling angle. The second part of the design process is to choose the geometry of the grating that gives maximum coupling efficiency based on rigorous analyses. The diffraction gratings are fabricated by recording the interference between two waves in photoresist. The waveguide is fabricated from silicon nitride that is deposited by chemical vapor deposition. The diffraction grating recording assembly is described along with the grating coupler fabrication process. A grating coupler is fabricated with an input coupling efficiency of 15% at a coupling angle of 22.9°. The results also show that the light is being coupled into the nitride waveguide indirectly. The light is coupled first into a photoresist slab and then into the nitride waveguide through modal coupling and scattering. An analysis of the structure explains the coupling, and rigorous analyses are given to show that the measured results are in accordance with theory.

Silk fibroin is a widely studied material in the context of tissue engineering. Thanks to its versatility and impressive properties, the fields where silk fibroin is used have grown. In particular, silk fibroin has proved to be useful in all the cases when an interface with living tissues is needed (e.g. biophotonics, bioelectronics). As a consequence of this increasing interest, a wide range of protocols have been developed to prepare different materials starting from cocoons. The aim of this thesis is to investigate new strategies to fabricate silk fibroin-based materials, either improving previously developed protocols or proposing new methodologies both with the purpose to overcome certain limitations of current approaches and to propose new areas of application. We choose to work on three topics: the production of patterns using photolithography on a fibroin photoresist films (fibroin photocrosslinkable photoresist, FPP), the production of sponges made from a chemically modified version of the native protein (Methacrylated fibroin, Sil-MA), and the production of a solid bulk resin made starting from the regenerated protein. In the case of the FPP (and its counterpart made of sericine, SPP) the fabrication of films and pattern was restricted to the use of harsh chemicals. In addition, the resulting material had a roughness that limits its use in optical applications, making the determination of the refractive index (RI) not possible. The novelty of our work consisted in the modification of the original protocol to make it environmentally sustainable and to decrease the roughness in order to use ellipsometry to determine the RI dispersion. The broadly used silk-based sponges can be prepared by several protocols but they all suffer of the same limitations: the sponges are stabilized only by physical crosslinking (the change from the random to the crystalline secondary structure), and there are no clear models that correlate the sponge properties to their composition. We produced a new sponge, chemically crosslinked, whose stability was ensured by the creation, of chemical bonds between the protein chains during an UV curing. This task was accomplished using a simple protocol and a statistical method to model the composition-properties relations. The possibility to obtain a bulk, non-porous solid monolith from fibroin (solid-fibroin) has been received attention only in the last few years. This material is produced by a transition from solution to solid through solvent evaporation, a very slow process that takes weeks to be completed. The advantage of this transition is that it occurs at room temperature, allowing the addition of thermally degradable molecules (e.g. enzymes). We were able to optimize a procedure to produce the same material by compression of a silk sponge at high pressure and low temperature. The advantage of this method is the lower amount of time required to produce the material, minutes instead of days.