Neste trabalho é apresentada a simulação, fabricação e caracterização de filtros interferenciais empregando películas dielétricas amorfas depositadas pela técnica de deposição a vapor assistida por plasma (PECVD) sobre substratos de silício e de Corning Glass (7059). Os dispositivos ópticos foram construídos usando-se processos padrões de microeletrônica e consistiram em camadas periódicas com espessura e índice de refração apropriados para produzir picos da atenuação na transmitância da luz na região visível. Simulações numéricas precedentes foram realizadas baseando-se nas características ópticas das películas dielétricas. Para a caracterização dos filtros interferenciais, uma luz monocromática de um laser de He-Ne, foi injetada nos filtros e a luz obtida na saída foi conduzida então a um detector. O filtro depositado sobre Corning Glass (chamado de filtro vertical) e o filtro depositado sobre silício com cavidades (chamado de filtro suspenso) foram montados sobre dispositivos térmicos e angulares de modo a medir suas respostas à variação angular e térmica. Também, o filtro depositado sobre silício (chamado de filtro horizontal) foi montado sobre um dispositivo térmico, a fim de medir sua resposta à temperatura. Quando os filtros são submetidos a uma mudança na temperatura, uma variação do índice de refração devido ao efeito termo-óptico produz um deslocamento nos picos da atenuação, que podem ser previstos por simulações numéricas. Esta característica permite que estes dispositivos sejam usados como sensores termo-ópticos. Por outro lado, quando o filtro vertical e o filtro suspenso são submetidos a variações angulares entre a normal ao plano do filtro e o feixe de laser, uma variação na potência da luz de saída é produzida. Esta característica permite que estes dispositivos sejam usados como sensores angulares. / In this work, we present the simulation, fabrication and characterization of filters employing amorphous dielectric films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique on crystalline silicon and Corning Glass (7059) substrates. The optical devices were fabricated using standard microelectronic processes and consisted of periodic layers with appropriated thickness and refractive indexes to produce transmittance attenuation peaks in the visible region. For this, previous numerical simulations were realized based in the optical parameters of the dielectric films. For the characterization of the optical interferential filters, a monochromatic light, a He-Ne laser, was projected onto the filters and the transmitted output light was then conducted to a detector. The optical filters were produced on Corning Glass (here called vertical filter) and on silicon substrates. The silicon substrate was etch in KOH solution to form cavities and suspend part of the filter (here called suspended filter). The vertical and suspended filters were mounted on thermo and angular devices that allowed the measurement of the optical power as a function of temperature and angle changes. A second type of filter deposited over a silicon substrate (here called horizontal filter) was mounted on thermoelectric device, in order to control the temperature responses. When the filters are submitted to a change in temperature, a variation of the refractive index is originated in the dielectric film due to the thermo-optic effect (TOE), producing a shift in the attenuation peaks, which can be well predicted by numerical simulations. This characteristic allows these devices to be used as thermo-optic sensors. On the other hand, when the vertical filter and the suspended filter were subjected to an angular shift between the filter\'s normal and the laser, a variation of the output optical power is originated. This characteristic allows these devices to be used as angular sensors.

De par leurs propriétés remarquables, les nanotubes de carbone (NTCs) reçoivent beaucoup d’attention et de nombreuses recherches sont menées sur ces matériaux depuis les dernières décennies. Le nombre d'applications envisagées mais aussi la quantité demandée de NTCs augmentent chaque année. Pour atteindre une production à grande échelle et contrôlée, il est nécessaire d'avoir une bonne compréhension des mécanismes de croissance des NTCs. Dans ce manuscrit, la formation ainsi que l'activité catalytique de nanoparticules (NPs) par dépôt chimique en phase vapeur assisté par aérosol (CVD) sont étudiées expérimentalement, pour analyser le processus d'évolution des NPs et leur relation avec les NTCs.Dans le chapitre 1, nous présentons une introduction générale sur des structures, les méthodes de synthèse, les propriétés et les applications envisagées des NTCs, ainsi que l’état de l’art concernant l’étude des mécanismes de croissance des NTCs.Dans le chapitre 2, nous décrivons le système de dépôt chimique en phase vapeur avec catalyseur flottant, ainsi que les méthodes de diagnostic in-situ/ex-situ utilisées dans cette étude. La technique d’incandescence induite par laser (LII) est particulièrement importante dans ce chapitre, car cette technique nous permet de réaliser un diagnostic in situ sur la quantité/taille des NPs déposées pendant le processus de synthèse.Dans le chapitre 3, nous présentons l'évolution des NPs lors de la synthèse ainsi que les influences des différents paramètres de CVD (température, quantité de carbone/catalyseur, composition du gaz, etc.) sur les gouttelettes et les NPs respectivement. Un modèle pour la formation de NPs est proposé à la fin de ce chapitre.Dans le chapitre 4, les résultats des expériences sur l'évolution de la composition du gaz sont révélés. Ces résultats donnent des informations concernant les réactions chimiques ayant lieu dans la phase gazeuse lors de la synthèse des NTCs.Dans le chapitre 5, une étude détaillée de l'influence des paramètres de CVD sur les produits NTCs est menée, et les relations entre les NPs et les NTC sont discutées.Pour finir, des conclusions générales ainsi que les perspectives prévues pour les travaux futurs sont présentées. / Due to the outstanding properties in various aspects, carbon nanotubes (CNTs) received worldwide attentions and intensive investigations are carried out in the last decades. While the number of applications as well as the quantity demanded of CNTs are increasing year after year, to achieve large scale production of the desired structures in a controlled way, it is highly required having a clear understanding about the CNTs growth mechanism. In this study, the formation and catalytic activity of nanoparticles (NPs) under aerosol-assisted chemical vapor deposition (CVD) is experimentally investigated, aiming to study the NPs evolution process and their relation with the CNTs products.In chapter 1, we provide a general review of CNTs structures, synthesis methods, properties as well as applications. Moreover, the current situation of CNTs growth mechanism study is presented.In chapter 2, the floating catalyst chemical vapor deposition synthesis system, and the in-situ/ex-situ diagnostic methods used in this study are introduced. Laser induced incandescence technique (LII) is particularly explained in this chapter, which permits to achieve an in-situ diagnostic of the NPs quantity/size during the synthesis process.In chapter 3, the evolution of NPs during the synthesis is presented, in which the influences of different CVD parameters (temperature, carbon/catalyst quantity, gas composition etc.) on the droplets as well as on the NPs are investigated respectively. A NPs formation model is proposed based on the NPs variation information at the end of this chapter.In chapter 4, the experimental results of the gas composition evolution in chemical vapor deposition reactor are revealed, which reflect the gas phase chemical reactions information during the CNTs synthesis.In chapter 5, a detailed investigation about the influence of CVD parameters on the CNTs products is explained. And the relation between the NPs and CNTs is discussed.In the end, general conclusions are formed according to works and perspectives are provided for the improvement of the future work.

Dans les technologies avancées, l’épitaxie des matériaux à base de silicium devient de plus en plus critique et les effets morphologiques importants. Les traitements thermiques ainsi que le dopage peuvent altérer la morphologie des épitaxies dégradant de façon considérable les performances des dispositifs. Les travaux de thèse ont pour objectifs de comprendre et résoudre ces problématiques, ils concernent donc l’étude de la morphologie et des forts dopages des épitaxies dans les motifs de petites tailles des technologies CMOS 14 et 10 nm. Nous avons étudié l’influence des conditions de recuit sous H2 sur la morphologie des épitaxies. Ceci a conduit à la détermination de la cinétique d’arrondissement thermique dans les petits motifs (100 nm et moins). D’après une analyse de la cinétique, deux énergies ont été identifiées : 2,9 eV et 7,7 eV. L’énergie de 2,9 eV montre qu’aux hautes températures, la diffusion de surface est le principal mécanisme de l’arrondissement thermique. Aux faibles températures, l’augmentation de la couverture d’hydrogène limite encore plus cette diffusion, augmentant fortement l’énergie obtenue. Nous avons observé que la pression du gaz porteur et la nature de celui-ci ont un impact important sur la diffusion de surface et modulent donc la cinétique d’arrondissement thermique. La caractérisation par microscopie à force atomique de croissances sélectives de couches SiGe dopées bore, montre que le bore modifie grandement la morphologie de croissance, ainsi que l’arrondissement thermique. Pour un même recuit, un motif dopé s’arrondit beaucoup plus rapidement qu’un motif non dopé. Les épitaxies développées au cours de ces travaux ont été intégrées avec succès dans les sources/drains du CMOS 14 nm. Selon le besoin, les épitaxies peuvent soit présenter de larges facettes bien définies soit aucune facette, et cela grâce à un procédé adéquat que ce travail a permis de proposer et développer / In advanced technologies, the Si-based materials epitaxy becomes more and more challenging and the morphological effects very important. The thermal treatments as well as the doping may degrade the epitaxies’ morphology resulting in considerably damaging the devices’ performances. The works presented in this thesis, aim at understanding and solving these problematics. Thus, they are focused on the study of the epitaxies’ morphology and high doping in the small patterns of the 10 and 14 nm CMOS technologies. The influence of the H2 annealing conditions on the morphology was studied. This led to determine the thermal rounding kinetics in small patterns. According to a kinetics analysis, two energies were identified: 2.9 eV and 7.7 eV. The 2.9 eV energy shows that at high temperatures, the surface diffusion is the thermal rounding main mechanism. At low temperatures, the hydrogen coverage’s increase limits even more this diffusion, greatly increasing the energy obtained. It was observed that the carrier gas pressure and its nature have a strong impact on the surface diffusion and thus modify the thermal rounding kinetics. The characterization by atomic force microscopy, of boron doped layer selectively grown, shows that the boron greatly modifies the growth’s morphology, as well as the thermal rounding. Considering a same annealing, the rounding phenomenon occurs faster in a doped pattern than in an un-doped pattern. The epitaxies developed during this work were successfully integrated to the 14 nm node sources and drains. Depending on the needs, the epitaxies can either present large and well defined facets or no facets, all of this thanks to an adequate process which was proposed and developed through this work.

<p>Metastable (Ti,Si)N alloy and TiN/SiNx multilayer thin solid films as well as SiNx/TiN surfaces have been explored. Cubic Ti1-xSixN (0≤x≤0.14) films deposited onto cemented carbide (WC-Co) substrates by arc evaporation exhibited a competitive columnar growth mode where the structure transforms to a feather-like nanostructure with increasing Si content as revealed by x-ray diffraction and transmission electron microscopy. X-ray photoelectron spectroscopy revealed the presence of Ti-N and Si-N bonding, but no amorphous Si3N4. Band structure calculations showed that phase separation of NaClstructure Ti1-xSixN solid solution into cubic SiN and TiN phases is energetically favorable. The metastable microstructure, however, was maintained for the Ti0.86Si0.14N film annealed at 900°C, while recrystallization in the cubic state took place at 1100°C annealing during 2h. The Si content influenced the film hardness close to linearly, by combination of solid-solution hardening in the cubic state and defect hardening. For x=0 and x=0.14, nanoindentation gave a hardness of 29.9±3.4 GPa and 44.7±1.9 GPa, respectively. The hardness was retained during annealing at 900°C.</p><p>Nanostructured materials, e.g., nanocomposites and nanolaminates, are defined by internal interfaces, of which the nature is still under debate. In this work two-phase model systems were explored by depositing SiNx/TiN nanolaminate films, including superlattices containing cubic SiNx, by dual target reactive magnetron sputtering. It is demonstrated that the interfacial phase of SiNx onto TiN(001) and TiN(111) can be crystalline, and even epitaxial with complex surface reconstructions. Using in situ structural analyses combined with ab initio calculations, it is found that SiNx layers grow epitaxially, giving rise to strong interfacial bonding, on both TiN(001) and TiN(111) surfaces. In addition, TiN overlayers grow epitaxially on SiNx/TiN(001) bilayers in nanolaminate structures. These results provide insight into the development of design rules for novel nanostructured materials.</p> / Report code: LiU-TEK-LIC-2006:51.

<p>This thesis is based on experimental studies in chemical physics. Titanium dioxide (TiO₂) and phthalocyanine’s (Pc’s), interesting in many future perspectives, have been deposited as thin films and studied as follows. Information has been obtained on e.g. molecular orientation, crystal structure, depth profile of the chemical composition, electrochemical properties and electronic structure. This has been achieved by means of a combination of techniques: X-ray photoelectron spectroscopy (XPS), near edge x-ray absorption fine structure (NEXAFS), density functional theory calculations (DFT), UV-visible absorption spectroscopy (UVVIS) and cyclic voltammetry (CV).</p><p>Metal-free phthalcyanine (H₂Pc) has been shown to form films with different crystal structure and molecular orientation depending on deposition method, evaporation/sublimation or powder deposition, on commercial conducting glass (fluorine doped tin oxide, FTO), which is used e.g. in solar cells and organic light emitting devices (OLEDs). The unoccupied molecular orbitals are divided in x, y and z space coordinates of the molecule and also divided in inequivalent nitrogen components. </p><p>The electronic structure is also studied for a sublimated titanyl phthalocyanine (TiOPc) film and related to the metal-free phthalocyanine. The ligand field around the titanium atom in TiOPc is compared with that of TiO₂ to delineate the unoccupied levels recorded by means of x-ray absorption spectroscopy.</p><p>Nanostructured TiO₂ films were manufactured by screen printing/doctor blading on FTO. Such films were additionally covered with lutetium diphthalocyanine (LuPc₂) by means of surface assembly from solution. LuPc₂^-, LuPc₂⁺ and LuPc₂H were identified and the stability of the electrochromic reactions in this system was monitored.</p><p>Chemical vapor deposition (CVD) has been used to grow nanometer sized anatase TiO₂ crystals on pre-oxidized Si (111) without formation of interfacial carbon and with an interface layer of the size of 15- 25Å. The interface layer was found to be amorphous TiSi_xO_y with graded stoichiometry. </p>

This thesis deals with the main aspects in chemical vapordeposition (CVD) of silicon (Si) and silicon-germanium (Si1-xGex) films for high-speed bipolar transistors.In situdoping of polycrystalline silicon (poly-Si)using phosphine (PH3) and disilane (Si2H6) in a low-pressure CVD reactor was investigated toestablish a poly-Si emitter fabrication process. The growthkinetics and P incorporation was studied for amorphous Si filmgrowth. Hydrogen (H) incorporated in the as-deposited films wasrelated to growth kinetics and the energy for H2desorption was extracted. Film properties such asresistivity, mobility, carrier concentration and grain growthwere studied after crystallization using either furnaceannealing or rapid thermal annealing (RTA). In order tointegrate an epitaxial base, non-selective epitaxial growth(NSEG) of Si and SiGe in a lamp-heated single-waferreduced-pressure CVD reactor was examined. The growth kineticsfor Si epitaxy and poly-Si deposition showed a differentdependence on the deposition conditions i.e. temperature andpressure. The growth rate difference was mainly due to growthkinetics rather than wafer surface emissivity effects. However,it was observed that the growth rate for Si epitaxy and poly-Sideposition was varying during growth and the time-dependencewas attributed to wafer surface emissivity variations. A modelto describe the emissivity effects was established, taking intoconsideration kinetics and the reactor heating mechanisms suchas heat absorption, emission andconduction. Growth ratevariations in opening of different sizes (local loading) andfor different oxide surface coverage (global loading) wereinvestigated. No local loading effects were observed, whileglobal loading effects were attributed to chemical as well astemperature effects. Finally, misfit dislocations formed in theSiGe epitaxy during NSEG were found to originate from theinterface between the epitaxial and polycrystalline regions.The dislocations tended to propagate across the activearea. <b>Keywords:</b>chemical vapor deposition (CVD), bipolarjunction transistor (BJT), heterojunction bipolar transistor(HBT), silicon-germanium (SiGe), epitaxy, poly-Si emitter,in situdoping, non-selective epitaxy (NSEG), loadingeffect, emissivity effect

Heterojunction bipolar transistors (HBT) based on SiGeC havebeen investigated. Two high-frequency architectures have beendesigned, fabricated and characterized. Different collectordesigns were applied either by using selective epitaxial growthdoped with phosphorous or by non-selective epitaxial growthdoped with arsenic. Both designs have a non-selectivelydeposited SiGeC base doped with boron and a poly-crystallineemitter doped with phosphorous. Selective epitaxial growth of the collector layer has beendeveloped by using a reduced pressure chemical vapor deposition(RPCVD) technique. The incorporation of phosphorous and defectformation during selective deposition of these layers has beenstudied. A major problem of phosphorous-doping during selectiveepitaxy is segregation. Different methods, e.g. chemical orthermal oxidation, are shown to efficiently remove thesegregated dopants. Chemical-mechanical polishing (CMP) hasalso been used as an alternative to solve this problem. The CMPstep was successfully integrated in the HBT process flow. Epitaxial growth of Si1-x-yGexCy layers for base layerapplications in bipolar transistors has been investigated indetail. The optimization of the growth parameters has beenperformed in order to incorporate carbon substitutionally inthe SiGe matrix without increasing the defect density in theepitaxial layers. The thermal stability of npn SiGe-based heterojunctionstructures has been investigated. The influence of thediffusion of dopants in SiGe or in adjacent layers on thethermal stability of the structure has also been discussed. SiGeC-based transistors with both non-selectively depositedcollector and selectively grown collector have been fabricatedand electrically characterized. The fabricated transistorsexhibit electrostatic current gain values in the range of 1000-2000. The cut-off frequency and maximum oscillation frequencyvary from 40-80 GHz and 15-30 GHz, respectively, depending onthe lateral design. The leakage current was investigated usinga selectively deposited collector design and possible causesfor leakage has been discussed. Solutions for decreasing thejunction leakage are proposed. <b>Key words:</b>Silicon-Germanium-Carbon (SiGeC),Heterojunction bipolar transistor (HBT), chemical vapordeposition (CVD), selective epitaxy, non-selective epitaxy,collector design, high-frequency measurement, dopantsegregation, thermal stability.

Most electrical, magnetic or optical devices are today based on several, usually extremely thin layers of different materials.  In this thesis chemical synthesis processes have been developed for growth of less stable and metastable layers, and even multilayers, of nickel containing compounds. A chemical vapor deposition (CVD) method for deposition of metastable Ni3N has been developed.  The deposition process employs ammonia as nitrogen precursor. An atomic layer deposition (ALD) process for deposition of both polycrystalline and epitaxial NiO and using low oxygen activity, has also been developed. Both deposition processes utilizes bis(2,2,6,6-tetramethyl-3,5-heptanedionato)nickel(II) (Ni(thd)2) as the metal precursor. The Ni3N deposition proceeds via surface reactions. The growth rate is very sensitive to the partial pressure of ammonia, why adsorbed –NHx species are believed to be of importance for the film growth. Similar reactions can be expected between the metal precursor and H2O. For ALD of NiO a large excess of water was needed For the multilayered structures of Ni3N/NiO, growth processes, working at low activities of oxygen and hydrogen, are needed to avoid oxidation or reduction of the underlying layer. Chemical vapor growth methods such as CVD and ALD are often suffering from using high activities of hydrogen or oxygen to deposit metals and oxides. An alternative deposition pathway for metal deposition, without any hydrogen in the vapor, has been demonstrated. The metal has been formed by decomposition of the metastable nitride Ni3N in a post-annealing process.  Ni3N decomposes via different mechanisms, depending on environment in the annealing process. The different mechanisms result in different degrees of ordering in the resulting Ni films. From the knowledge gained about the chemical growth of NiO and Ni3N as well as the decomposition of Ni3N, well-defined multilayer structures have been produced in different combinations of NiO, Ni3N and Ni.

This thesis is based on experimental studies in chemical physics. Titanium dioxide (TiO2) and phthalocyanine’s (Pc’s), interesting in many future perspectives, have been deposited as thin films and studied as follows. Information has been obtained on e.g. molecular orientation, crystal structure, depth profile of the chemical composition, electrochemical properties and electronic structure. This has been achieved by means of a combination of techniques: X-ray photoelectron spectroscopy (XPS), near edge x-ray absorption fine structure (NEXAFS), density functional theory calculations (DFT), UV-visible absorption spectroscopy (UVVIS) and cyclic voltammetry (CV). Metal-free phthalcyanine (H2Pc) has been shown to form films with different crystal structure and molecular orientation depending on deposition method, evaporation/sublimation or powder deposition, on commercial conducting glass (fluorine doped tin oxide, FTO), which is used e.g. in solar cells and organic light emitting devices (OLEDs). The unoccupied molecular orbitals are divided in x, y and z space coordinates of the molecule and also divided in inequivalent nitrogen components. The electronic structure is also studied for a sublimated titanyl phthalocyanine (TiOPc) film and related to the metal-free phthalocyanine. The ligand field around the titanium atom in TiOPc is compared with that of TiO2 to delineate the unoccupied levels recorded by means of x-ray absorption spectroscopy. Nanostructured TiO2 films were manufactured by screen printing/doctor blading on FTO. Such films were additionally covered with lutetium diphthalocyanine (LuPc2) by means of surface assembly from solution. LuPc2-, LuPc2+ and LuPc2H were identified and the stability of the electrochromic reactions in this system was monitored. Chemical vapor deposition (CVD) has been used to grow nanometer sized anatase TiO2 crystals on pre-oxidized Si (111) without formation of interfacial carbon and with an interface layer of the size of 15- 25Å. The interface layer was found to be amorphous TiSixOy with graded stoichiometry.

As the integration scale of transistors/devices in a chip/system keeps increasing, effective cooling has become more and more important in microelectronics. To address the thermal dissipation issue, one important solution is to develop thermal interface materials with higher performance. Carbon nanotubes, given their high intrinsic thermal and mechanical properties, and their high thermal and chemical stabilities, have received extensive attention from both academia and industry as a candidate for high-performance thermal interface materials. The thesis is devoted to addressing some challenges related to the potential application of carbon nanotubes as thermal interface materials in microelectronics. These challenges include: 1) controlled synthesis of vertically aligned carbon nanotubes on various bulk substrates via chemical vapor deposition and the fundamental understanding involved; 2) development of a scalable annealing process to improve the intrinsic properties of synthesized carbon nanotubes; 3) development of a state-of-art assembling process to effectively implement high-quality vertically aligned carbon nanotubes into a flip-chip assembly; 4) a reliable thermal measurement of intrinsic thermal transport property of vertically aligned carbon nanotube films; 5) improvement of interfacial thermal transport between carbon nanotubes and other materials. The major achievements are summarized. 1. Based on the fundamental understanding of catalytic chemical vapor deposition processes and the growth mechanism of carbon nanotube, fast synthesis of high-quality vertically aligned carbon nanotubes on various bulk substrates (e.g., copper, quartz, silicon, aluminum oxide, etc.) has been successfully achieved. The synthesis of vertically aligned carbon nanotubes on the bulk copper substrate by the thermal chemical vapor deposition process has set a world record. In order to functionalize the synthesized carbon nanotubes while maintaining their good vertical alignment, an in situ functionalization process has for the first time been demonstrated. The in situ functionalization renders the vertically aligned carbon nanotubes a proper chemical reactivity for forming chemical bonding with other substrate materials such as gold and silicon. 2. An ultrafast microwave annealing process has been developed to reduce the defect density in vertically aligned carbon nanotubes. Raman and thermogravimetric analyses have shown a distinct defect reduction in the CNTs annealed in microwave for 3 min. Fibers spun from the as-annealed CNTs, in comparison with those from the pristine CNTs, show increases of ~35% and ~65%, respectively, in tensile strength (~0.8 GPa) and modulus (~90 GPa) during tensile testing; an ~20% improvement in electrical conductivity (~80000 S m⁻¹) was also reported. The mechanism of the microwave response of CNTs was discussed. Such an microwave annealing process has been extended to the preparation of reduced graphene oxide. 3. Based on the fundamental understanding of interfacial thermal transport and surface chemistry of metals and carbon nanotubes, two major transfer/assembling processes have been developed: molecular bonding and metal bonding. Effective improvement of the interfacial thermal transport has been achieved by the interfacial bonding. 4. The thermal diffusivity of vertically aligned carbon nanotube (VACNT, multi-walled) films was measured by a laser flash technique, and shown to be ~30 mm² s⁻¹ along the tube-alignment direction. The calculated thermal conductivities of the VACNT film and the individual CNTs are ~27 and ~540 W m⁻¹ K⁻¹, respectively. The technique was verified to be reliable although a proper sampling procedure is critical. A systematic parametric study of the effects of defects, buckling, tip-to-tip contacts, packing density, and tube-tube interaction on the thermal diffusivity was carried out. Defects and buckling decreased the thermal diffusivity dramatically. An increased packing density was beneficial in increasing the collective thermal conductivity of the VACNT film; however, the increased tube-tube interaction in dense VACNT films decreased the thermal conductivity of the individual CNTs. The tip-to-tip contact resistance was shown to be ~1×10⁻⁷ m² K W⁻¹. The study will shed light on the potential application of VACNTs as thermal interface materials in microelectronic packaging. 5. A combined process of in situ functionalization and microwave curing has been developed to effective enhance the interface between carbon nanotubes and the epoxy matrix. Effective medium theory has been used to analyze the interfacial thermal resistance between carbon nanotubes and polymer matrix, and that between graphite nanoplatlets and polymer matrix.