Дисертації з теми "Substrate transfert"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Substrate transfert".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Argoud, Maxime. "Mécanismes de collage et de transfert de films monocristallins dans des structures à couches de polymères." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00848111.
Gorantla, Sandeep, Alicja Bachmatiuk, Jeonghyun Hwang, Hussain A. Alsalman, Kwak Joon Young, Thomas Seyller, Jürgen Eckert, Michael G. Spencer, and Mark H. Rümmeli. "A universal transfer route for graphene." Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A36288.
Zhang, Shuangfeng. "Wide Bandgap Semiconductor Components Integration in a PCB Substrate for the Development of a High Density Power Electronics Converter." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS398/document.
The emerging wide bandgap (WBG) semiconductor devices have been developed for power conversion applications instead of silicon devices due to higher switching frequencies (from few 100 kHz to several MHz) and lower on-state losses resulting in a better efficiency. In order to take full advantage of the WBG components, PCB technology is attractive for high power density integration thanks to its flexibility and low cost. However, due to poor thermal conductivity of the commonly used material Flame Retardant-4 (FR4), efficient thermal solutions are becoming a challenging issue in integrated power boards based on PCB substrates. So it is of the first importance to seek technological means in order to improve the thermal performances. In this thesis, three main thermal management solutions for PCB structures have been investigated including thermal vias, thick copper thickness on the PCB substrate as well as thermoelectric cooling (TEC) devices. Our studies are based on the electro-thermal modeling and 3D finite element (FE) methods. Firstly, optimization of the thermal via parameters (via diameter, via plating thickness, via-cluster surface, via pattern, pitch distance between vias etc.) has been realized to improve their cooing performances. We presented and evaluated thermal performances of the PCB structures by analyzing the thermal resistance of the PCB substrate with different thermal vias. Secondly, it is found that thermal performances of the PCB structures can be enhanced by using thick copper thickness on top of the PCB substrate, which increases the lateral heat flux along the copper layer. Influences of the copper thickness (35 µm to 500 µm) has been discussed. This solution is easy to realize and can be combined with other cooling solutions. Thirdly, thermoelectric cooler like Peltier device is a solid-state cooling technology that can meet the local cooling requirements. Influences of Peltier parameters (Thermoelectric material properties, number of Peltier elements, distance between the heating source and the Peltier devices etc.) have been identified. All these analyses demonstrate the potential application of Peltier devices placed beside the heating source for PCB structures, which is a benefit for developing the embedding technology in such structures
Kambhampati, Patanjali. "Adsorbate-substrate charge transfer excited states /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Danyal, Karamatullah. "Electron Transfer and Substrate Reduction in Nitrogenase." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2181.
Bouillaud, Hugo. "Fabrication et optimisation des caractéristiques thermiques de diodes Schottky de la filière GaAs et reportées sur SiHR pour des applications de multiplication de fréquences." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILN043.
The exponential needs associated with applications exploiting the THz domain require to expand the range of available sources and optimize their fabrication processes. In this thesis, we focused on schottky diodes for its use as frequency multipliers. Our experimental research involved optimizing the characteristics of GaAs schottky diodes through the development and implementation of an innovative fabrication process. First, we fabricated GaAs schottky diodes on GaAs substrate with several aspect ratios in order to make a reference in terms of device. Then we fabricated a flip-chip device for a 150 GHz frequency multiplication application in a waveguide block. Finally, in order to enhance the power handling of the diodes, we optimized their thermal dissipation by transferring their epitaxial structure onto a substrate with higher thermal conductivity : SiHR (high resistivity silicon). The complete technological processes for these fabrications are detailed, and the last part of the study is dedicated to their characterization. On one hand, we assessed any variations in the characteristics of GaAs diodes on GaAs induced by the different aspect ratios. On the other hand, we compared the two technologies on SiHR and GaAs substrates. This work demonstrates the potential of this type of transferred technology, where a significant reduction of thermal resistance is observed and is associated with a notable improvement of the series resistance
Thiam, Ndèye Arame. "Etude et développement de transistors bipolaires à hétérojonctions InP/GaAsSb reportés sur Si en vue de l’amélioration de la dissipation thermique." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10168/document.
The InP heterojonctions bipolar transistors (HBT) offer today cut-off frequencies larger than 400GHz for the InP / GaAsSb system. Thanks to these performances, these transistors are used for the realization of successful circuits in millimeter-wave applications such as the optical communications. So, to reach these remarkable performances, the HBT are subject to a notorious self-heating phenomenon due to high current density of collector. This thesis thus has for object the study and the development of InP / GaAsSb HBT transferred on a host substrate of silicon with the aim of the improvement of the thermal behavior. We report first of all the principles of the bipolar transistor as well as the state of the art of the various materials used for fast transistors. A transfer technique of epitaxial layers was then presented. We study bounding problems resulting from the chosen technique and transfer parameters for valid thermo-compression at low temperature were optimized. The development of InP / GaAsSb transferred technology on silicon was then made. In particular, the collector contact realization has needed particular attention. Active layers thickness reduction as well as device fabrication process technology allowed reaching transition frequency Ft higher than 400GHz. The study of HBT thermal behavior was finally presented with thermal resistance extraction. Very low values were obtained on the transferred technology, from 800 to1300 W/K.m according to transistors size; these values are very close to those obtained by TCAD simulation for such a technology. It is the first measurement on InP / GaAsSb transferred-HBT on high thermal conductivity silicon substrate. This transfer technology has so allowed thermal resistance improvement of 70 % compared with that of standard HBT technology. This work leads to the influence of transferred-substrate for the severe reduction of self-heating in bipolar transistors technology
De, vecchy Jon. "Réalisation de substrats innovants à partir de diamant." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALT022.
Within a global aim of reducing energy consumption, microelectronics components must be more efficient and less energy-consuming. Power electronics, which converts electric power, is particularly concerned because its component must operate at high intensity, voltage and temperature. Silicon, the base material of these components, is reaching its limits and the conception of components made with other materials is currently being studied. Among the candidate materials, diamond and its outstanding properties is of great interest. Its excellent thermal conductivity (2200 W/m/K) combined with high breakdown field (10 MV/cm) and high hole mobility (2000 cm²/V/s) are attractive for making smaller and more efficient components.However, monocrystalline diamond synthesis methods are limiting substrate size to about 15 x 15 mm², thus preventing its industrialization. The approach developed in this thesis is the diamond layer transfer to another substrate by adapting the Smart Cut^TM process. This process is based on a combination of ion implantation and bonding of the implanted substrate to a receiving substrate. Annealing then causes the fracture of the implanted substrate and the detachment of a film (with controlled thickness) which is transferred to the receiving substrate. This approach would make it possible to reduce component cost by decreasing diamond consumption and to open the way to industrialization thanks to successive transfers on a large substrate.Smart Cut^TM must be fully adapted to the diamond case, studies of each step will thus be presented. Blistering observation on the implanted substrate surface after annealing is the very first step of ion implantation parameters adaptation. A blistering process using combinations of hydrogen ion implantation and annealing will be presented.Diamond transformations occurring during the process will be characterized. Full layer transfer studies using substrate bonding will then be presented. Finally, prospects for optimization and realization will be given
Carlmark, Anna. "Atom transfer radical polymerization from multifunctional substrates." Licentiate thesis, KTH, Polymer Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1447.
Atom transfer radical polymerization (ATRP) has proven to be a powerful technique to obtain polymers with narrow polydispersities and controlled molecular weight. It also offers control over chain-ends. The technique is the most studied and utilized of thecontrolled/”living” radical polymerization techniques since a large number of monomerscan be polymerized under simple conditions. ATRP can be used to obtain polymer graftsfrom multifunctional substrates. The substrates can be either soluble (i. e. based ondendritic molecules) or insoluble (such as gold or silicon surfaces). The large number ofgrowing chains from the multifunctional substrates increases the probability of inter-and intramolecular reactions. In order to control these kinds of polymerizing systems, andsuppress side-reactions such as termination, the concentration of propagating radicalsmust be kept low. To elaborate such a system a soluble multifunctional substrate, based on 3-ethyl-3-(hydroxymethyl)oxetane, was synthesized. It was used as a macroinitiatorfor the atom transfer radical polymerisation of methyl acrylate (MA) mediated byCu(I)Br and tris(2-(dimethylamino)ethyl)amine (Me6-TREN) in ethyl acetate at room temperature. This yielded a co-polymer with a dendritic-linear architecture. Since mostsolid substrates are sensitive to the temperatures at which most ATRP polymerisations are performed, lowering the polymerization temperatures are preferred. ATRP at ambienttemperature is always more desirable since it also suppresses the formation of thermally formed polymer. The macroinitiator contained approximately 25 initiating sites, which well mimicked the conditions on a solid substrate. The polymers had low polydispersity and conversions as high as 65% were reached without loss of control. The solid substrateof choice was cellulose fibers that prior to this study not had been grafted through ATRP.As cellulose fibers a filter paper, Whatman 1, was used due to its high cellulose content.The hydroxyl groups on the surface was first reacted with 2-bromoisobutyryl bromidefollowed by grafting of MA. Essentially the same reaction conditions were used that hadbeen elaborated from the soluble substrate. The grafting yielded fibers that were very hydrophobic (contact angles>100°). By altering the sacrificial initiator-to-monomer ratiothe amount of polymer that was attached to the surface could be tailor. PMA with degreesof polymerization (DP’s) of 100, 200 and 300 were aimed. In order to control that thepolymerizations from the surface was indeed “living” a second layer of a hydrophilicmonomer, 2-hydroxymethyl methacrylate (HEMA), was grafted onto the surface. Thisdramatically changed the hydrophobic behavior of the fibers.
QC 20100524
Voisin, Jérémy. "Influence des pratiques de recharge des aquifères par des eaux pluviales sur les communautés microbiennes des nappes phréatiques." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1113/document.
In urban area, managed aquifer recharge (MAR) systems raises hydrological connectivity between surface and groundwater. These infiltration practices are the cause of many disturbances in groundwaters (e.g. increase of thermal variations, decrease of dissolved oxygen or enrichment in organic matter) but associated consequences on microbial compartment remains unclear. The main aim of the thesis is to determine the effects of stormwater runoff infiltration on microbial communities of groundwater, in terms of abundance, activities and bacterial diversity. Based on environmental changes associated to MAR practices and bacterial community analyses, a fundamental question is to assess the importance of dispersal (e.g. transfers) and selection by abiotic factors (e.g. nutrients availability) on groundwater communities assemblage. This study is based on field experiments with two complementary strategies of sampling: an active one (i.e. groundwater sampling) and a passive one (incubation of artificial substrate). Communities’ description was made by next-generation sequencing (i.e. Illumina MiSeq) of rrs gene. The results showed a significant influence of MAR practices on microbial communities. Growth, activities and diversity of groundwater micro-organisms were mainly stimulated by biodegradable dissolved organic carbon enrichment associated to MAR practices. Nonetheless, this impact was reduced in systems where the vadose zone is thick (> 10 m) and acts as a physical, chemical and biological filter between the infiltration basin and the aquifer. Low similarities between bacterial communities of infiltration waters and bacterial communities of groundwaters reveal that vadose zone is effective on the retention of bacteria in studied systems. To conclude, this thesis constitutes the first major study that aimed to quantify microbial compartment response to disturbances caused by MAR practices in urban area. It also opens new perspectives on assessment tool for groundwater quality
Riachy, Lina. "Nouvelle technique de nanoscopie de fluorescence par excitation non radiative pour l’étude des interactions membrane/substrat." Thesis, Troyes, 2017. http://www.theses.fr/2017TROY0017/document.
The objective of my thesis work was to develop a new technique of Non-radiative Excitation Fluorescence Microscopy to study the interactions membrane/substrate.This technique is achieved by coating the substrate with donor species, such as quantum dots (QDs). Thus the dyes are not excited directly by the laser source, as in common fluorescence microscopy, but through a non-radiative energy transfer.To prevent dewetting of the donor film, we have implemented a silanization process to covalently bond the QDs on the substrate. A monolayer of QDs was then deposited on only one side of the coverslips. We highlight the potential of our method through the study of Giant Unilamellar Vesicles (GUVs) labeled with DiD as acceptor, in interaction with surface functionalized with poly-L-lysine. In the presence of GUVs, we observed together a quenching of QDs emission and emission of DiD located in the membrane, which clearly indicated that non-radiative energy transfer from QDs to DiD occurs. By changing salt concentration in the solution, we have been able to finely control the force of the interaction and thus modify the equilibrium distance between the surface and the membrane. From quantitative measurements of quenching of QDs and fluorescence emitted by non-radiative transfer, we calculate the equilibrium distances and obtain a mapping of these distances with a nanometric optical resolution. Based on this study, our functionalization technique is also used to observe the adhesion of living cells, U87MG on different surfaces in order to observe their focal points
amini, manesh navid. "HEAT TRANSFER IN MULTI-LAYER ENERGETIC NANOFILM ON COMPOSITES SUBSTRATE." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3191.
M.S.
Department of Mechanical, Materials and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering MSME
Amini, Manesh Navid. "Heat transfer in multi-layer energetic nanofilm on composites substrate." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4587.
ID: 030422800; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2010.; Includes bibliographical references (p. 140-149).
Ph.D.
Doctorate
Department of Mechanical, Materials and Aerospace Engineering
Engineering and Computer Science
Beynon, David George. "Plate to substrate ink transfer in the flexographic printing process." Thesis, Swansea University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595861.
Mailleur, Alexandra. "Évaporation de goutte sur substrat soluble." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1268/document.
Recent progresses have led to a better understanding of the mechanisms driving the evaporation kinetics of a sessile droplet of simple liquid on an inert substrate. For instance, the influence of the contact angle of the droplet, of the thermal conductivity of the solid, of its roughness, of the thermocapillary convection inside the droplet, or of the convection in the vapor are now better understood. Besides, the way coffee-stain-like deposits form during the evaporation of complex fluids (colloidal suspension, blood …) has now been studied in detail.All these studies have been carried out with non-reacting solids. We propose here the investigation of the behavior of a water droplet evaporating on a soluble substrate. In this configuration, three phenomena are strongly interacting: dissolution/precipitation of the substrate at the solid-liquid interface, diffusion/convection of the dissolved species in the droplet, evaporation of water at the liquid-air interface. We have worked with fast-dissolving solids, NaCl and KCl single crystals, with controlled temperature and humidity. To test the influence of thermogravitational instabilities, experiments on the ground and in microgravity (parabolic flights) have been carried out.We have observed that the dissolution induces a pinning of the triple line at the early beginning of the evaporation, leading to a decrease of the contact angle linear in time. At the end of the evaporation, a peripheral deposit (coffee-ring-like) resulting from the salt migration and precipitation, is always present, proof of an outward flow inside the droplet. The observation of drops seeded with fluorescent particles evaporating on a dissolving solid (NaCl single crystal) has highlighted complex capillary flows inside the liquid. The shape of this ring-like deposit is very diversified and vary with the substrate temperature and the initial volume of the droplet
Simoni, Stefano Federico. "Factors affecting bacterial transport and substrate mass transfer in model aquifers /." [S.l.] : [s.n.], 1999. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13232.
Widayatno, Tri. "Micropattern transfer without photolithography of substrate : Ni electrodeposition using enface technology." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2293.
Malytska, Iuliia. "Exploring bipolar electrochemistry for the modification of unusual conducting substrates." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0135/document.
Bipolar electrochemistry is a phenomenon based on the polarization of conductive objects in an electric field. In contrast to conventional electrochemistry, the drop of potential in the electrolyte solution triggers the involved redox reactions. When a conductive object is positioned in an electric field present in a solution between two feeder electrodes, it is polarized and becomes a bipolar electrode. The potential difference between the electrolyte and the bipolar electrode is the driving force for reduction/oxidation reactions at the two extremities of the bipolar electrode; oxidation will occur at one end, combined simultaneously with reduction at the other end.Bipolar electrochemistry is a concept that allows generating an asymmetric reactivity at the surface of a conductive object. During the last decade, bipolar electrochemistry found many applications such as the synthesis of asymmetric micro- and nano-particles, electrodeposition, sensing, propulsion of microobjects, electroanalysis etc. The advantage of this technique is its wireless character, which allows the modification of delicate materials and also to electrochemically address many objects simultaneously.In the present thesis, the approach was applied to different semiconducting materials and biological systems. In addition, properties of substrates of different nature have been studied using bipolar electrochemistry.In this way, it was possible to create metal deposits on organic charge transfer salts in a site-specific way. The resulting hybrid metal/organic particles were tested for the asymmetric generation of photovoltage under illumination.Inorganic transition metal dichalcogenides were also used as a substrate for bipolar electrochemistry. Deposition of different metals on MoSe2 macroparticles was performed. Transition metal dichalcogenides are known for their catalytic activity with respect to hydrogen evolution reaction. Therefore, wireless hydrogen production on MoSe2 crystals and microparticles could be demonstrated by using bipolar electrochemistry. In the latter case it is possible to envision their use for electrochemical decontamination of solutions in the bulk.Finally, bipolar electrochemistry has also been used for studying the conductivity of biological molecules (DNA). The primary goal was to develop a new approach for the asymmetric modification of DNA by metal nanoparticles. Experiments were performed by using either Capillary Assisted Bipolar Electrodeposition (CABED) with the DNA molecules present in the bulk, or by immobilizing DNA as stretched entities on model surfaces for subsequent modification. Encouraging first results could be evidenced by TEM or AFM measurements
Helzer, Jennifer Jill. "The Italian ethnic substrate on Northern California : cultural transfer and regional identity /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Pellegrini, Erika. "Dissection of enzymatic phosphoryl transfer : from substrate recognition to the transition state." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/4326/.
Murphy, Christine Fecenko Thorp H. Holden. "Coupled electron proton transfer reactions in biological redox active substrates." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2895.
Title from electronic title page (viewed Jun. 23, 2010). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
Mrad, Mona. "Transfer Printing and Cellulose Based substrates for modern Textile Printing." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-159745.
Bashforth, Pauline S. "Mathematical modelling of interactions between a hot liquid and a cold horizontal substrate." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294615.
Borel, Franck. "Contributions à l'étude des interactions entre les ARNtser et la séryl-ARNt synthétase d'Escherichia coli et de Saccharomyces cerevisiae." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10142.
Madduma-Liyanage, Kumudu C. "Reactions of Pt(IV) and Pd(IV) Complexes with Multi-Electron Substrates." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416570506.
Beix, Vincent. "Etudes des procédés d'encapsulation hermétique au niveau du substrat par la technologie de transfert de films." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-01037897.
Brault, Sébastien. "Etude du procédé de transfert de filmsApplications : Encapsulation sur tranche et élaboration de micro-dispositifs (thèse Cifre IEF-KFM technology)." Paris 11, 2010. http://www.theses.fr/2010PA112100.
Generally microsystems require to be inserted in an environment perfectly controlled in order to allow an optimum functioning process (vacuum for example when the quality factor must be high) or to be able to connect its exit characteristics to the operating conditions. It is thus important to be able to place them in a perfectly adapted packaging of protection. Before that, the device must be cut out in the silicon substrate. This cutting step is critical because it requires the use of a fluid jet on surface which can involve the partial or complete damage device or cause the sticking effect of microdevices on the substrate. We imagined an original film transfer process on the device in order to ensure the MEMS protection during this cutting step. This process uses the transfer technology, namely that micro-caps are elaborate on a specific substrate then separated of this substrate to protect to micro-structures on the final substrate. More largely, this universal process makes it possible to carry out a very great choice of microdevices (Pirani gauges for example). Thus, this process was fully qualified for packaging applications then extended to microstructures transfer
Chajara, Khalil. "Mécanisme d'action de l'oxygène moléculaire sur des substrats dièniques en présence de catalyseurs rédox paramagnétiques." Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30024.
Khalil, Hassan. "Diffusion de la chaleur dans un substrat de verre recouvert d'un film mince d'4he et d'3he." Nice, 1994. http://www.theses.fr/1994NICE4733.
Loghmari, Fahmi. "Solidification de gouttes impactant un substrat solide." Paris 6, 2009. http://www.theses.fr/2009PA066280.
The subject of this dissertation is the impingement and simultaneous heat transfer ans soldification of droplet on a flat substrate. The process of the impact and solidification of a droplet on a solid substrate is governed by the dynamics's impact, heat transfer between splat and substrate and the phase change involved in the solidification of a molten droplet. The main novel feature of this PhD thesis is that each physical process was studied individually. The aim of the study is to examine the influence of various parameters specific to the droplet and the substrate on the final splat's morphology. A critical issue of numerical models based on equilibrium solidification during the phase change material affects the accuracy of results. Indeed, the impact velocity of molten metal droplets in plasma sprayed coatings can vary from 1 m/s up to 100 m/s. In these cases, the cooling rate is so high (about 108 K/s) that stands for rapid solidification, which can lead to new metastable crystalline phases and amorphous solid phases. A significant result of this thesis is the numerical study of a rapid solidification of an Indium droplet during its spreading on a flat substrat. The cooling is based on a model's heat transfer taking into account the phenomenon of phase change with non-equilibrium solidification model determined through DSC experiments results
Abou, Daher Mahmoud. "Réalisation et optimisation de transistors HEMT GaN forte puissance et haute fréquence par technologie de transfert de couches sur substrat hôte." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30046.
Wireless telecommunication market largely benefits from new nitride technologies, which reach outstanding performance compared with traditional technologies. Current research is opening up many new strategies and alternative solutions to address simultaneously antagonist considerations such as cost, performances and/or reliability. Most AlGaN / GaN HEMTs are fabricated on a low cost, highly resistive silicon substrate or on a much more expensive and supply sensitive SiC substrate. However, the electrical performance constraints required when these technologies are integrating into radar systems, satellites and in telecommunications systems make them dependent to the operating temperature parameter, mainly linked to the high power dissipation during static/dynamic energy transfer. Indeed, these components are capable of generating high power densities in the microwave range. However, the operating frequency increase leads an increase of the power dissipation, generating the self-heating phenomenon which influences the devices performance (ID,max,ft,fmax...). In this context, several solutions were already proposed in the literature (use of composite substrates, passivation of devices, etc.). Furthermore, the layer transfer technology to report HEMTs from growth substrate onto a host substrate with a good thermal conductivity (such as diamond substrate) is a promising solution, still poorly detailed to date. The objective of this thesis work is to improve the heat dissipation and thus the performance and reliability of high-frequency HEMT transistors by using a layer transfer technology. AlGaN / GaN heterostructures are grown on a silicon substrate by MOCVD at CHREA. After the fabrication of HEMTs on a silicon substrate, AlGaN / GaN devices (for which the silicon substrate has been removed) are transferred onto a CVD diamond substrate. This transfer is obtained by thermocompression bonding of sputtered AlN layers on each surface to be assembled (backside of the transistors and diamond substrate). This transfer process has not damaged the functionality of the transistors with short gate length (Lg = 80 nm). The AlGaN/GaN HEMTs with a 2x35 µm development transferred onto diamond of feature a current ID,max = 710 mA.mm-1, a cutoff frequency ft of 85GHz and an oscillation frequency fmax of 144GHz. However, this transfer technique requires optimization phases (especially to reduce thickness and improve the crystalline quality and thermal conductivity of AlN layers) in order to reduce the thermal resistance of this adhesion layer and to limit the self-heating phenomenon noted at the end of this thesis work
Hery, Travis M. "Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68842.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 24).
Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further optimized using superhydrophobic surfaces. For superhydrophobic condensation, a structured silicon surface with pillars 2.1 p.m tall, 200 nm in diameter, and a 400 nm pitch was tested. By removing noncondensable gases (NCG) from the system by means of a steam trap, the heat transfer rates of DWC and SHC were found to be greater than that of filmwise condensation (FWC) by a factor of 2, but indistinguishable from each other. The effect of NCG leads to a 5x reduction in heat transfer rates for both DWC and SHC. DWC heat transfer rates are as much as 50 kW/m 2 less than FWC at the same temperature difference, representing a 25% reduction. However, the SHC heat transfer rates remain above those of FWC by as much as 50 kW/m² at the same temperature difference, representing a 20% improvement. These studies suggest that SHC may be a useful passive method to improve condensation heat transfer rates in the presence of NCG. However, it remains to be seen if SHC can provide better heat transfer rates than DWC under saturated steam conditions.
by Travis M. Hery.
S.B.
Hines, Daniel R. "Organic electronics with polymer dielectrics on plastic substrates fabricated via transfer printing." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7685.
Thesis research directed by: Dept. of Chemical Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Peach, Philip James. "Enantioselective transfer hydrogenation of novel substrates with emphasis on the dynamic kinetic resolution : transfer hydrogenation of cyclic ketones." Thesis, University of Warwick, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397260.
Terassa, Laura Anna Maria [Verfasser], Christian [Akademischer Betreuer] Mair, and Bernd [Akademischer Betreuer] Kortmann. "Morphological simplification in Asian Englishes : : frequency, substratum transfer, and institutionalization." Freiburg : Universität, 2019. http://d-nb.info/1178321495/34.
Sarma, Ranjana. "Investigations of nucleotide-dependent electron transfer and substrate binding in nitrogen fixation and chlorophyll biosynthesis." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/sarma/SarmaR1209.pdf.
Ghosh, Arijit. "Degradation of polymer/substrate interfaces - an attenuated total reflection Fourier transform infrared spectroscopy approach." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1291130563.
Demarre, Gaëlle. "Etude des intégrases d' intégrons : nature des substrats et relations structure / fonction." Paris 6, 2005. http://www.theses.fr/2005PA066291.
Villalobos, Oliver Susana Patricia. "Approches expérimentales et théoriques du comportement dynamique de cycles de substrats binaires." Compiègne, 1990. http://www.theses.fr/1990COMPD301.
Leboeuf, Sébastien. "Dynamic wetting and heat transfer behaviour of aluminium droplets impinging and solidifying on copper substrates." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81548.
Zerrad, Myriam. "Nouveaux développements de la technique de diffusion lumineuse : substrats transparents, BRDF résolue spatialement, échantillons colorés." Phd thesis, Université Paul Cézanne - Aix-Marseille III, 2007. http://tel.archives-ouvertes.fr/tel-00385428.
Friedrich, Nadine. "Untersuchungen zum Transfer von anorganischen und organischen Schadstoffen aus dotiertem Substrat in Gemüsepflanzen (Tomaten, Paprika)." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2011. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-73396.
Ben, Salk Soukaina. "Graphène et matériaux 2D : techniques de transfert, fabrication d'hétérostructures et applications." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I031.
The high theoretical mobility of graphene makes it an excellent material for radio frequency applications. However, this mobility is limited by structural defects introduced by material growth techniques, the transfer method from metallic substrates to hosting semiconductor substrates, the fabrication processes of devices as well as the interaction of graphene with hosting substrate. This thesis aims to address these issues in order to make graphene practically insensitive to its environment. There are mainly two parts involved in this work: (i) Transfer by electrochemical exfoliation (wet transfer) of millimetre size single domains of graphene (~ 5mm) synthesized by CVD as well as their physical and electrical characterization; this study is part of an exchange program between the IEMN and the University of Irvine-California (PUF-Partner University Funding Program-on the development of flexible electronics). (ii) Fabrication and characterization of hBN/Graphene/hBN heterostructures by dry transfer of exfoliated materials. Although the CVD (Chemical Vapor Deposition) method made it possible to obtain large single crystals of graphene on copper; the mandatory transfer to SiO2 substrate generally introduces defects and contaminations in graphene resulting in low performance devices. A reliable transfer system for CVD graphene is developed and optimized for cleanroom use. The method used is based on an electrochemical exfoliation approach known as Bubble transfer. By optimizing this approach, we were able to transfer graphene single domains without structural defects. Finally, the electrical characterization of devices based on the transferred graphene crystal made it possible to obtain a relatively low contact resistance owing to the good quality of the transferred graphene. In order to limit the interaction of graphene with its environment and thus preserve its high mobility, encapsulation with hexagonal boron nitride hBN makes it possible to satisfy this need. The fabrication of these Van der Waals heterostructures is performed using mechanically exfoliated materials because the growth of large areas hBN is still considered a great scientific challenge. An experimental nano-manipulation platform “Stamping set-up” dedicated to the stacking of 2D materials is developed (from design to realization) as well as a process for graphene encapsulation by dry transfer. Different samples have been successfully fabricated using monolayer and bilayer graphene. Morphological and structural characterizations have shown that graphene after encapsulation shows very low doping values and uniform strain at the nanometre scale; which promises high mobility values. This work paves the way towards obtaining high quality graphene which is an important part for the development of electronic devices based on heterostructures of 2D materials
Deng, Hao. "Détermination des flux thermiques et de la température du système revêtement-substrat en cours de projection thermique." Besançon, 2003. http://www.theses.fr/2003BESA2001.
The purpose of this work is to study influence of the auxiliary means (pre-heating and cooling) used during thermal spray on temperature field and properties (residual stresses status, microhardness and interfacial adherence) of coating-substrate system. A study relying on the specification of function permitted to confirm the feasibility and the reliability of the method of inverse heat transfer problem (IHTP). An extension of the function specification method was applied to determine scanning rate of the process HEATCOOL®. Through the study of the conjugate gradient method, a modified method synthesizing two traditionhal methods for a plan problem has been proposed. The influence of the number of thermocouples, the initial value, the mesh density and the stopping criterion on precision and convergent speed of numerical calculation has been studied systematically. An optimal configuration was then used to determine the profiles of the thermal fluxes such as heating and cooling sources. These results have been verified quantitatively using bi-sample set-up and qualitatively while the study on the scanning rate. The simulation of instantaneous temperature field during the realization of the first layer has showed the difference in temperature at the interface of coating-substrate for the two systems considered (NiCrBSi/Stainless steel and ZrO2-8%Y2O3/ Stainless steel), but also the interest of CO2-liquid like a cooling means. Lastly, the coatings carried out by the process HEATCOOL® revealed the better performances in residual stresses status, microhardness and adherence than those carried out by the classical configurations (single spray and spray accompanied by a cooling)
O'Hern, Sean C. (Sean Carson). "Development of process to transfer large areas of LPCVD graphene from copper foil to a porous support substrate." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68952.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 57-62).
In this thesis, I present a procedure by which to transfer greater than 25 mm² areas of high-quality graphene synthesized via low-pressure chemical vapor deposition from copper foil to porous support substrates. Large-area, high quality graphene on a porous support would serve as a platform by which to create high efficiency porous graphene membranes for use in liquid and gas-phase separation technologies. In this procedure, we transfer greater than 25 mm² areas of graphene with few holes and tears to both gold Quantifoil Holey Carbon transmission electron microscope grids with 1.2 [mu]m diameter pores and to Sterlitech polycarbonate track etch membranes with 200 nm diameter pores by bonding the substrates to the graphene then wet-etching the copper. The resulting membrane quality is characterized via Raman spectroscopy, scanning electron microscopy, diffraction patterning, and aberration-corrected scanning transmission electron microscopy.
by Sean C. O'Hern.
S.M.
Chabrol, Virginie. "Functionalized latex particles as substrates for metal mediated radical polymerization." Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-01012004.
Panek, Joel C. "Fragmentation of brittle polymeric toner line caused by swelling of paper substrate during immersion in water." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/5808.
Breitenbach, Jan [Verfasser], Cameron [Akademischer Betreuer] Tropea, Ilia V. [Akademischer Betreuer] Roisman, and Günter [Akademischer Betreuer] Brenn. "Drop and spray impact onto a hot substrate: Dynamics and heat transfer / Jan Breitenbach ; Cameron Tropea, Ilia V. Roisman, Günter Brenn." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2018. http://d-nb.info/1175583871/34.
Frugier, Magali. "Manipulation des identites des acides ribonucleiques de transfert : etude d'arnt a identites multiples et de substrats minimalistes de la reaction d'aminoacylation." Université Louis Pasteur (Strasbourg) (1971-2008), 1994. http://www.theses.fr/1994STR13072.
Milos̆ević, Nenad. "Mesure de la diffusivité thermique et de la résistance de contact thermique des couches minces sur des substrats par la méthode impulsionnelle." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0025/these.pdf.
The purpose of this work is to revise and improve one, as well as establish and develop the other pulse method for the measurements of thermal diffusivity and thermal contact resistance of thin layers deposited on substrate. To carry out this mission, the work was directed to following three axes: 1. Theoretical studies, having included both analytical and also numerical resolutions of heat conduction differential equations, for the corresponding initial and boundary conditions. 2. Numerical studies, having contained methods and procedures of parameter estimation, being applied in the particular problem. 3. Experimental studies, having implied modifications and development of the experimental setup, as well as execution of different experiments. In the first direction, one established several models that corresponded to one- ant two-dimensional heat conduction through a tow-layered system, implying general and particular initial and boundary conditions. In the second direction, for a study of the estimation possibilities of unknown parameters, as it was the thermal diffusivity of thin layer, in the presence of the uncertainties of known parameters, one applied and developed two different estimation procedures: first, direct, with original parameters, and the second, optimal, with modified parameters. Finally, in the third direction, one studied experimental problems, appropriate to the experimental setup and measurement itself, established another setup for two-dimensional measurements, and applied these devices, procedures, and thermal models obtained from the previous studies, to real different samples with thin layers