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Spectroscopic ellipsometry charactarization of single and multilayer aluminum nitride / indium nitride thin film systemsKhoshman, Jebreel M. January 2005 (has links)
Thesis (Ph.D.)--Ohio University, June, 2005. / Title from PDF t.p. Includes bibliographical references (p. 221-234)
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Development of a novel growth method for AlN bulk single crystals using elemental aluminum and nitrogen gas / Al元素と窒素ガスを用いたAlNバルク単結晶の新規成長方法の開発Wu, Peitsen 24 September 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19311号 / 工博第4108号 / 新制||工||1633(附属図書館) / 32313 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 川上 養一, 教授 髙岡 義寛, 教授 藤田 静雄 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Interactions between austenite grain boundaries and aluminum nitride precipitatesDogan, Omer Nihat January 1990 (has links)
No description available.
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COLD ELECTRON EMITTERS BASED ON POLYCRYSTALLINE DIAMONDSAMIEE, MAHMOOD 13 July 2005 (has links)
No description available.
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Synthesis of ultrafine aluminum nitride powders in a flow reactorAzeez, Qaisar A. January 1988 (has links)
No description available.
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Models for predicting powder-polymer properties and their use in injection molding simulations of aluminum nitrideKate, Kunal H. 13 December 2012 (has links)
Powder injection molding (PIM) is widely used to manufacture complex-shaped ceramic and metal components in high production volumes. In order to design and fabricate PIM components, it is important to know a number of material properties at different powder- polymer compositions. In this thesis, several predictive models for estimating rheological, thermal and mechanical properties as a function of powder-polymer mixtures were evaluated using experimental data obtained from the literature. Based on this survey, models were selected for predicting rheological, thermal and mechanical properties for aluminum nitride-polymer mixtures at various volume fractions of powder using experimental measurements of unfilled and filled polymers. The material properties were estimated for two aluminum nitride powder-polymer mixtures and used in mold-filling simulations. These results will provide new perspectives and design tools for identifying useful material compositions, component geometry attributes, and process parameters while eliminating expensive and time-consuming trial-and-error practices prevalent in PIM. / Graduation date: 2013
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Bulk crystal growth, characterization and thermodynamic analysis of aluminum nitride and related nitridesDu, Li January 1900 (has links)
Doctor of Philosophy / Department of Chemical Engineering / James H. Edgar / The sublimation recondensation crystal growth of aluminum nitride, titanium
nitride, and yttrium nitride were explored experimentally and theoretically. Single
crystals of these nitrides are potentially suitable as substrates for AlGaInN epitaxial
layers, which are employed in ultraviolet optoelectronics including UV light-emitting
diodes and laser diodes, and high power high frequency electronic device applications.
A thermodynamic analysis was applied to the sublimation crystal growth of
aluminum nitride to predict impurities transport (oxygen, carbon, and hydrogen) and to
study the aspects of impurities incorporation for different growth conditions. A source
purification procedure was established to minimize the impurity concentration and avoid
degradation of the crystal’s properties. More than 98% of the oxygen, 99.9% of hydrogen
and 90% of carbon originally in the source was removed. The AlN crystal growth process
was explored in two ways: self-seeded growth with spontaneous nucleation directly on
the crucible lid or foil, and seeded growth on SiC and AlN. The oxygen concentration
was 2 ~ 4 x 1018cm-3, as measured by secondary ion mass spectroscopy in the crystals
produced by self-seeded growth. Crystals grown from AlN seeds have visible grain size
expansion. The initial AlN growth on SiC at a low temperature range (1400°C ~1600°C)
was examined to understand the factors controlling nucleation. Crystals were obtained
from c-plane on-axis and off-axis, Si-face and C-face, as well as m-plane SiC seeds. In all
cases, crystal growth was fastest perpendicular to the c-axis.
The growth rate dependence on temperature and pressure was determined for TiN
and YN crystals, and their activation energies were 775.8±29.8kJ/mol and
467.1±21.7kJ/mol respectively. The orientation relationship of TiN (001) || W (001) with
TiN [100] || W [110], a 45o angle between TiN [100] and W [100], was seen for TiN
crystals deposited on both (001) textured tungsten and randomly orientated tungsten. Xray
diffraction confirmed that the YN crystals were rock-salt structure, with a lattice
constant of 4.88Å. Cubic yttria was detected in YN sample from the oxidation upon its
exposed to air for limited time by XRD, while non-cubic yttria was detected in YN
sample for exposures more than one hour by Raman spectra.
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Transmission electron microscopy study on the formation of SiNX interlayer during InAlN growth on Si (111) substrateKuei, Chun-Fu January 2015 (has links)
Ternary indium aluminum nitride (InXAl1-XN) semiconductor is an attractive material with a wide-range bandgap energy varied from ultraviolet (Eg(AlN): 6.2 eV) to near infrared (Eg(InN): 0.7 eV). With tuning composition, it can be widely used to many optoelectronic device applications. In this thesis, I have studied InXAl1-XN film deposited on Si (111) substrate using natural and isotopically enriched nitrogen as reactive gas by reactive magnetron sputter epitaxy (MSE). Four series of experiments were performed, which are I. InAlN presputtering, II. InAlN sputter deposition, III. InAlN direct deposition, and IV. InAlN direct deposition using isotopically enriched nitrogen. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The θ-2θ XRD scan confirms that the designed composition x = 0.17 of InXAl1-XN film was obtained. TEM images shows that an amorphous interlayer with a thickness ranging from 1.2 nm to 1.5 nm was formed between Si substrate and InXAl1-XN film. However, high-resolution TEM shows that the interlayer actually contains partial crystalline structures. EDX line profile indicates that the chemical composition of the amorphous interlayer is silicon nitride (SiNX). By comparing d-spacing measurement of partial crystalline structures with EDX line profile, it reveals that partial SiNX crystal is formed in the interlayer. Nonetheless, the samples (IAD01, IAD02, IAD03, IAD04), grown without presputtering procedure, contain both crystalline SiNX and InXAl1-XN embedded in the amorphous interlayer. It means that SiNX and InXAl1-XN film can be directly grown on the substrate in the beginning of deposition. Moreover, the samples (IAD01, IAD03), quenched directly after deposition, have less crystalline structures in the interlayer then the samples (IAD02, IAD04), maintained at 800℃ for 20 min.
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Estudo de materiais piezoelétricos da família III-V obtidos por sputtering reativo visando sua aplicação em sensores e MEMS. / Study of III-V piezoelectric materials obtained by reactive sputtering for sensors and MEMS applications.Pelegrini, Marcus Vinícius 18 August 2010 (has links)
Neste trabalho, apresento um estudo sobre a fabricação e caracterização físico-química de filmes finos de nitreto de alumínio (AlN) obtidos pela técnica de pulverização catódica reativa por rádio frequência (r.f sputtering) utilizando um alvo de alumínio puro. Visto que o AlN é um material que apresenta piezoeletricidade e compatibilidade com a tecnologia MOS, o objetivo principal desse trabalho é definir os parâmetros de processo de deposição que resultem em um material com propriedades adequadas para sua utilização como elemento atuador e/ou sensor em sistemas micro eletromecânicos (MEMS). O estudo da influência dos parâmetros de processo foi realizado em três etapas. Na primeira realizei um estudo preliminar sobre a influência da pressão de processo e potência de r.f. Na segunda etapa realizei um estudo sobre a influência da relação entre o gás reativo (N2) e o pulverizante (Ar) nas características físicoquímicas do material. Na 3º etapa estudei o efeito da temperatura de deposição nas características do filme que apresentou as propriedades mais propícias para aplicações em MEMS. Propriedades como índice de refração, composição química e stress residual não apresentaram grandes variações com a mudança da composição gasosa da atmosfera de deposição, no entanto, os resultados de difração de raios-X mostraram que os filmes obtidos com 30% de N2 possuem maior cristalização na direção que apresenta maior piezoeletricidade, sendo assim, mais favorável para ser utilizado como sensor/atuador na fabricação de MEMS. No estudo sobre o efeito da temperatura de deposição verificamos que o filme crescido a 250°C apresentou as melhores propriedades para as aplicações em MEMS desejadas. Para finalizar o trabalho a constante piezoelétrica de carga foi obtida utilizando capacitores de placas paralelas de molibdênio e o AlN como dielétrico, obtendo um coeficiente piezoelétrico de carga d33 de 0,5 pm/V. / I present a study on the production and physicochemical characterization of aluminum nitride thin films (AlN) obtained by r.f. reactive magnetron sputtering, using a target of pure aluminum. Since AlN is a material that presents piezoelectricity and compatibility with MOS technology, the main objective of this work is to define the process parameters that will result in a material with properties suitable for its use as an actuator / sensor in micro electromechanical systems (MEMS). The process parameters influence study was performed in three steps. First I conducted a preliminary study on pressure process and rf power influence. In the second step was studied the influence of the reactive (N2) and sputtering (Ar) gas ratio on the material physical and chemical properties. Last but not least, I studied the temperature deposition effects in the AlN thin film obtained in the gas ratio which presented the most favorable properties for MEMS applications. Properties such as refractive index, chemical composition and residual stress did not show considerable variations with changing in the atmosphere deposition, however X-ray diffraction results showed films obtained with 30% N2 have higher crystallization in (002) direction, which is the one with greater piezoelectricity response and thus, more favorable to be used as sensor / actuator in MEMS fabrication. The study on deposition temperature effects has shown maximum (002) crystallization direction is achieved in films grown at 250° C. Piezoelectric coefficient was defined using parallel plate capacitors method using AlN as dielectric resulted in a d33 piezoelectric coefficient of 0,5 pm/V.
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Produção e caracterização de filmes de nitreto de alumínio e sua aplicação em guias de onda tipo pedestal. / Fabrication and characterization of aluminum nitride films and its application in pedestal-type optical waveguides.Armas Alvarado, Maria Elisia 28 April 2017 (has links)
O presente trabalho tem como objetivo principal a produção e estudo de filmes de nitreto de alumínio (AlN) depositados por pulverização catódica (sputtering) reativa e a fabricação e caracterização de guias de onda tipo pedestal utilizando o AlN como núcleo. Inicialmente, filmes de AlN foram fabricados por pulverização catódica reativa (sputtering) de rádio frequência (RF) utilizando um alvo de alumínio (Al) com 99,999% de pureza, e nitrogênio (N2) como gás reativo. Subsequentemente, os filmes foram caracterizados mediante as técnicas de elipsometria, difração de raios X (DRX), espectroscopia de absorção por transformada de fourier na região do infravermelho (FTIR) e espectroscopia de absorção na região do ultravioleta e do visível (UV-VIS). Tendo as melhores condições ópticas e físicas para a deposição de filmes de AlN, foram fabricados neste trabalho guias de onda tipo pedestal utilizando estes filmes como núcleo. O guia de onda pedestal traz um processo de fabricação alternativo, em que a geometria do guia de onda determina-se na camada anterior ao do núcleo, assim já não é necessário delinear as paredes laterais da camada de núcleo facilitando desta forma, o processo de fabricação do dispositivo. Os guias de tipo pedestal fabricados neste trabalho foram definidos através da corrosão parcial do óxido de silício (SiO2) mediante a técnica de RIE (Reactive Ion Etching) usando gases trifluorometano (CHF3) e oxigênio (O2) como gases reativos. Uma vez definido o pedestal, um filme de nitreto de alumínio é depositado sobre o SiO2 com a finalidade de constituir o núcleo do guia de onda. O ar foi utilizado como revestimento superior, cujo índice de refração (n = 1) aumenta o confinamento da luz no núcleo e também para poder possibilitar a caracterização das perdas ópticas do dispositivo. Para esta caracterização usamos a técnica de vista superior que permitiu a análises das perdas ópticas de propagação para diferentes alturas de pedestal e diferentes espessuras de núcleo tanto para filmes de AlN orientado no plano cristalino (002) quanto para filmes de AlN amorfos. / The main objective of this work is the production and study of Aluminum Nitride (AlN) films deposited by reactive sputtering and the fabrication and characterization of pedestal optical waveguides using AlN as core. Initially, aluminum nitride films were produced by reactive sputtering using a 99.999% aluminum (Al) purity target, and nitrogen (N2) as the reactive gas. Subsequently, the films were characterized by ellipsometry, X-ray Diffraction, Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet-visible spectroscopy (UV-VIS). Once the best optical and physical conditions for the deposition of AlN films were obtained, pedestal waveguides using these films as a nucleus were fabricated in this work. The pedestal waveguide provides an alternative manufacturing process where the geometry of the waveguide is determined in the pre-core layer, so it is no longer necessary to delineate the side walls of the core layer thereby facilitating the device fabrication process. The pedestal waveguides fabricated in this work were defined by the partial corrosion of SiO2 by the RIE (Reactive Ion Etching) technique using CHF3 and O2 gases as reactive gases. Once the pedestal is completed, an aluminum nitride film is deposited onto the SiO2 layer as the waveguide core. The air was used as an upper cladding, whose refractive index (n ? 1) increases the confinement of the light in the core and also allows the optical loss characterization. For this characterization, we used the superior view technique that allowed the analysis of optical propagation losses for different pedestal heights and different core thicknesses for both highly (002) oriented and amorphous AlN films.
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