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PAPERS

CRECIMIENTO DE PELÍCULAS DELGADAS DE NITRURO DE CARBONO POR DEPOSICION CON LÁSER PULSADO  
Hemos crecido películas delgadas de nitruro de carbono (CNx) mediante el Deposición por Láser Pulsado (DLP), usando como blanco grafito de alta pureza y como substrato silicio. Las películas fueron crecidas en un ambiente de gas de nitrógeno, variando la presión del gas, para dos valores de la fluencia del láser y dos valores de la temperatura del substrato. Estas películas fueron caracterizadas por Microscopia de Fuerza Atómica (AFM) y espectroscopia Raman. La rugosidad de las películas depende tanto de la presión del gas de trabajo como de la temperatura del substrato, sus estructuras son amorfas presentando los picos D y G, típicos de las estructuras tipo fulereno.

http://www.redalyc.org/articulo.oa?id=84903624
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AFM, Espectroscopia FTIR y RAMAN de Películas Delgadas de CNx Crecidas por PLD  
Amorphous carbon nitride thin films (a-CNx) were deposited from a pyrolytic graphite (99.999%) target in nitrogen atmosphere on Si (100) substrate at different temperatures and gas pressure by Pulsed Laser Deposition (PLD) technique. The films were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Atomic Force Microscope (AFM). The FTIR analysis shows the presence of peaks above 2200 cm-1 associated with sp1 C�ßN triple bonds and the frequency range 1440.1650 cm-1with the sp2 C=C and C=N modes. Raman spectra show an amorphous structure and intensity ratio of D to G peak, ID/IG increases with increasing deposition nitrogen gas pressure and substrate temperature. The AFM microgram presents a smoothness and uniformity, which follows a high quality of films.

http://dialnet.unirioja.es/servlet/articulo?codigo=3182966
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Characterization by XRD and UV-VIS spectrophotometry of ZnO film deposited by PLD  
ZnO films were deposited by pulsed laser ablation employing different temperatures and gas pressures. It was used as a target a tablet made from available commercial ZnO powder. The films were grown on glass substrates treated by chemical Cleanliness. The samples were
characterized by X ray diffraction and Uv-Vis spectrophotometry as a function of substrate temperature and gas pressure. The ZnO exhibits hexagonal wurtzite structure with preferential orientation along c-axis direction. It was found that the best quality films were obtained at substrate temperature of 300ºC and at gas pressure of 26,7 Pa. At room temperature films exhibit ZnO hexagonal phase with low crystallinity. At low pressures thin films do not generate ZnO phases.
Descriptors: ZnO, PLD, XRD, UV-Vis. Spectrophotometer

http://faccbi.ucp.edu.co/ecei/attachments/128_Caracterizacion-por-DRX-y-espectrofotometria-UV-VIS-de-peliculas.pdf
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Chemical analysis of CNx thin films produced by pulsed laser ablation  
We present an investigation of the effect of the process parameters, namely deposition pressure, laser fluence and substrate temperature, on growth and bonding state of carbon nitride (CN"x) thin films deposited by Nd:YAG laser (1064nm) ablation of a graphite target in nitrogen atmosphere. Based on the comparative and quantitative analysis of changes in measured infrared spectroscopy (IR) versus X-ray photoelectron spectroscopy (XPS) spectra and on a critical review of the existing interpretation of IR and XPS data, a growth condition that lead to the synthesis of hard and elastics films having properties close to the those fullerene-like CN"x is proposed
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DETERMINATION OF PHYSICAL RESPONSE IN (Mo/AlN) SAW DEVICES  
This paper describes the experimental conditions in surface acoustic wave (SAW) designed on aluminum nitride (AlN) films grown on Si3N4 substrates by using pulsed laser deposition. Moreover it was studied the dependency of optical properties with temperature of deposition. The thickness, measured by profilometry technology, was 150 nm for all films. Moreover, SAW devices with a Mo/AlN/Si3N4 configuration were fabricated employing AlN buffer and Mo Channel. The morphology and composition of the films were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy analysis (XPS), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400–900 cm-1. In this work, a clear dependence in morphological properties, optical properties, frequency response and acoustic wave velocity as function of applied deposition temperature was found. It was also observed a reduction in reflectance of about 10% and an increase of acoustic wave velocity of about 1.2% when the temperature was increased from 200°C to 630°C.

Keywords: Aluminum nitride; pulsed laser deposition; optical reflectance; color purity frequency response; surface acoustic wave



Read More: http://www.worldscientific.com/doi/abs/10.1142/S0218625X13500170
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Optical Properties Dependence with Gas Pressure in AlN Films Deposited by Pulsed Laser Ablation  
AlN films were deposited by pulsed laser deposition technique (PLD) using an Nd: YAG laser (λ = 1064 nm). The films were deposited in a nitrogen atmosphere as working gas; the target was an aluminum high purity (99.99%). The films were deposited with a laser fluence of 7 J/cm2 for 10 minutes on silicon (100) substrates. The substrate temperature was 300 °C and the working pressure was varied from 3 mtorr to 11 mtorr. The thickness measured by profilometer was 150 nm for all films. The crystallinity was observed via XRD pattern, the morphology and composition of the films were studied using scanning electron microscopy (SEM) and Energy Dispersive X-ray analysis (EDX), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400 cm-1- 900 cm-1 by an Ocean Optics 2000 spectrophotometer. In this work, a clear dependence of the reflectance, dominant wavelength and color purity was found in terms of the applied pressure to the AlN films. A reduction in reflectance of about 55% when the pressure was increased from 3 mtorr to 11 mtorr was observed. This paper deals with the formation of AlN thin films as promising materials for the integration of SAW devices on Si substrates due to their good piezoelectric properties and the possibility of deposition at low temperature compatible with the manufacturing of Si integrated circuits.

http://adsabs.harvard.edu/abs/2011JPhCS.274a2119P
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STRUCTURAL AND MORPHOLOGICAL ANALYSIS OF ALUMINUM NITRIDE FILMS OF OBTAINED BY PULSED LASER DEPOSITION  
This paper gives the preliminary results about aluminum nitride (AIN) nanoestructured films deposited by pulsed laser deposition (PLD) technique, by using laser Nd:YAG (λ=1064), which hit a target of high purity aluminum (4N) in a nitrogen atmosphere. We used glass slide, Si3N4 (100) and Si (100) as substrates. The deposition time was 15 minutes at laser fluence 7 J/cm2 and room temperature. The thicknesses of thin films were 50 nm measured with a proflometer. The influence of nitrogen on thin films was studied by changing room gas pressure between 3 and 4 mTorr. Also we have studied the influence of substrate on morphological properties of AIN thin films. The film nanostructure was determined by scanning electron microscopy (SEM), atomic force microscopy (AFM) -the chemical composition- using the technique of energy dispersive X-ray (EDX). The crystal structure was examined with X-Ray Diffraction (XRD) to a 4 mTorr film on a Si3N4 (100) substrate giving a polycrystalline structure with reflections of planes (002), linked to the wurtzite-like structure of AIN.

Key words: aluminum nitride (AIN), pulsed laser deposition (PLD), XRD, SEM, EDX, proflometer, AFM.

http://www.sci.unal.edu.co/scielo.php?script=sci_arttext&pid=S0124-81702010000200007&lng=es&nrm=iso
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Películas delgadas de Nitruro de aluminio (AlN)  
Este documento pretende hacer una revisión de las principales características estructurales y morfológicas del nitruro de aluminio –AlN- específicamente cuando este es depositado por Magnetrón Sputtering ó por medio de Ablación Láser (PLD). Igualmente como influyen los parámetros de crecimiento como presión de gas ambiente (N2), temperatura de sustrato o tiempo de deposición en la calidad y orientación cristalina de las películas delgadas de AlN.

http://revistas.utp.edu.co/index.php/revistaciencia/article/view/1291
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Correlación Entre las Propiedades del Plasma y de las Películas de Cu Preparadas con Ablación Laser  
Se han estudiado los espectros emisión óptica del plasma decobre, producidos por un láser pulsado Nd:YAG de 1064 nm,con un ancho de pulso de 9 ns y una fluencia de 7 J/cm2.Con los plasmas de cobre se han crecido películas delgadassobre un sustrato amorfo (vidrio) a temperatura ambiente. Se ha variado la presión del gas ambiente, argón (9 mTorr, 100 mTorr, 150 mTorr y 200 mTorr). En el rango 480 nm a 530 nm del espectro de emisión del plasma de Cu se identifican las líneas espectrales, entre ellas las de mayor intensidad son las que le dan el color verde característico al plasma de cobre. Las líneas de emisión del cobre neutro (Cu I) son más intensas que las del ion de cobre (Cu II), la emisividad se incrementa con el aumento de la presión, debido a que el gas confina el plasma y aumenta el número de colisiones entre las especies generando más especies ionizadas y excitadas. En los espectros Raman de las películas delgadas de cobre con variación de presión se observan algunos picos entre 367 cm-1 y 602 cm-1, que se pueden analizar como picos correspondientes a enlaces Cu-O, lo que sugiere el proceso fácil de oxidación del Cu metálico, estos tienen un corrimiento al rojo que se puede interpretar como el efecto de los fonones en la red cristalina de la película.
El estudio morfológico de las películas por medio de SEMdemuestra que son películas suaves, lisas y con los resultadosde perfilometría se corrobora que son películas ultradelgadas.

Palabras clave

Espectroscopía de emisión óptica, crecimiento de películas delgadas, ablación láser, Cu, Raman, SEM, Optical Emission Spectroscopy, growth of thin films, laser ablation, Cu, Raman, SEM


http://biblioteca.ucp.edu.co/OJS/index.php/entrecei/article/view/1127
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Propiedades estructurales y ópticas de compuestos (AIN, GaN, InN)  
The purpose of this review article is to understand the technological advances and manufacturing of the nitrides of group III-V review structural and vibrational properties. In the section related optical energy gap prohibited and the lattice parameter with the energies of the vibrational modes. Currently the interest in nitrides of group III-V is due to it´s unique advantages in two key application areas: lightemitting diodes and high power electronics and high temperature. The Optoelectronics market is at 20 billion dollars currently per year, and is further expand rapidly in the next decade. Then we will describe the progress, perspectives, and Challenges in the Developments of new electronic and Optoelectronic devices based on nitrides of group III - V.

http://dialnet.unirioja.es/servlet/articulo?codigo=3945244
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Optical spectroscopy of emission from CN plasma formed by laser ablation  
The characterization of a plasma plume is a key issue in laser ablation and deposition studies. The formation, composition and propagation of laser-produced plasmas used for pulsed laser deposition (PLD) of CN have been studied under film growth conditions. The plume was generated by focusing 1064 nm, 9 ns pulses from Nd:YAG laser on carbon target under nitrogen ambient. We investigated the different species, such as CII, CI, C2, NII and CN, in laser ablated CN plasma using optical emission spectroscopy. The spectral characteristics of the plasmas were measured to determine the plasma properties as gas pressure was changed from 10-5 to 90 mTorr. The intensities of molecular species did not depend on gas ambient whereas ion intensities did. The vibrational temperature shows dependence with gas pressure.

http://iopscience.iop.org/1402-4896/2008/T131/014020
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PELÍCULAS DELGADAS NANOESTRUCTURADAS DE NITRURO DE ALUMINIO DEPOSITADAS POR ABLACIÓN LÁSER  
En este trabajo se ha depositado películas nanoestructuradas de AlN mediante el método de Deposición por Láser Pulsado (DLP) con un láser Nd:YAG (λ=1064 nm), en diferentes gases de trabajo (Nitrógeno), usando como blanco Aluminio de alta pureza y como sustrato portamuestras de vidrio y Si3N4 (100). La presión del gas ambiente se varió entre 0.39Pa y 1.46 Pa. Mientras la fluencia del láser se mantuvo constante a 7 J/cm2, la temperatura de los sustratos no se varió, en este caso se fijo en 25oC. El espesor de las películas en promedio fue de 75 nm, medido con un perfilometro, el tiempo de deposición fue de 15 minutos. La nanoestructuras y la morfología de las películas se estudiaron usando difracción de rayos X (DRX) y microscopia electrónica de barrido (SEM) al igual Espectroscopia de infrarrojos por transformada de Fourier FT-IR para todas las películas.
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DIAGNOSTICO DE UN PLASMA POR SONDA DE LANGMUIR  
Para las plumas en ablación láser, las cuales son significativamente ionizadas, la sonda de Langmuir ha demostrado ser una herramienta relativamente simple y barata para medir la forma de la pluma, la distribución de energía de los iones y la temperatura electrónica. En este trabajo describimos algunas consideraciones teóricas sobre el desarrollo de la sonda de Langmuir para el diagnóstico de la pluma del plasma producido por ablación láser.
http://www.redalyc.org/articulo.oa?id=84903576
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Zinc oxide nanostructured thin films  
En el presente artículo realizamos una detallada aunque breve revisión de trabajos de investigación con lo que ponemos de manifiesto las propiedades más relevantes de las estructuras de oxido de zinc, sus potenciales aplicaciones y algunas de las técnicas usadas para la caracterización de sus propiedades y métodos de crecimiento de las películas.
http://repositorio.utp.edu.co/dspace/handle/11059/721
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Estudio morfológico y estructural de películas delgadas de nitruro de aluminio obtenidas a partir de plasmas de aluminio en ambiente de N2  
Se han obtenido películas delgadas de AlN mediante el método de Deposición por Láser Pulsado (PLD) con un láser Nd:YAG (λ=1064 nm), en un gas reactivo (N2), usando como blanco aluminio de alta pureza (4N) y como sustrato Si3N4 (100). La presión del gas ambiente se varió de 4 mTorr y 5 mTorr. Mientras la fluencia del láser se mantuvo constante a 7 J/cm2. El espesor de las películas fue de 50 nm, medido con un perfilómetro, el tiempo de deposición fue de 10 minutos. La nanoestructura de las películas fue estudiada usando difracción de rayos X (DRX), el estudio morfológico se llevo a cabo por medio de las técnicas (AFM y SEM) y composicional (EDX). El tamaño de grano fue de 85,2 nm con una rugosidad de 3,8 nm para una presión de 5 mTorr y de 78,1 nm con una rugosidad de 6,7 nm para una presión de 4 mTorr ambas obtenidas a temperatura ambiente. Las especies presentes en el plasma fueron identificadas por medio de espectroscopia de emisión óptica (EOS), encontrándose las bandas AlN (0,0) y AlN (0,1) para una presión de nitrógeno de 4 mTorr.
http://revcolfis.org/ojs/index.php/rcf/article/view/440312
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Estudio Espectroscopico de Plasmas del Aire, Cobre y Aluminio  

In this paper we studied the main conditions for the Plasmas generation air, copper and aluminum, using
a laser Nd: YAG pulsed with wavelength 1064 nm with a pulse of 500 mJ Energy and 9 ns duration
at a repetition rate of 10 Hz. Through spectroscopy, we have analyzed Optical Emission lines Spectral
emission, which were obtained by varying the Atmospheric pressure. Emissivity to High pressure is
greater because of the confinement of the plasma and Increasing collisions between different species, in
the case Plasma in the air we compared the data obtained from each Wavelength due to each transition and
electronic state of Ionization with wavelengths characteristic of each Element reported by the database of
the NIST (National Institute of Standards and Technology).

http://www.revcolfis.org/publicaciones/vol40_1/4001176.pdf
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Spectroscopic study of emission coal mineral plasma produced by laser ablation  


Journal of Physics Conference Series 05/2014; 511(1):012063. DOI: 10.1088/1742-6596/511/1/012063
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ABSTRACT Spectroscopic analysis of plasma produced by laser ablation of coal samples using 1064 nm radiation pulses from a Q-switched Nd:YAG on different target under air ambient, was performed. The emission of molecular band systems such as C2 Swan System (d3Πg→a3Πu), the First Negative System N2 (Band head at 501,53 nm) and emission lines of the C I, C II, were investigated using the optical emission spectroscopy technique. The C2 molecular spectra (Swan band) were analyzed to determine vibrational temperature (0,62 eV); the density and electron temperature of the plasma have been evaluated using Stark broadening and the intensity of the nitrogen emission lines N II, the found values of 1,2 eV and 2,2 x1018 cm−3 respectively.
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Optical emission spectroscopy of Aluminum Nitride thin films deposited by Pulsed Laser Deposition  
Journal of Physics Conference Series 05/2014; 511(1):012078. DOI: 10.1088/1742-6596/511/1/012078


ABSTRACT In this work we study the Aluminium Nitride plasma produced by Nd:YAG pulsed laser, (λ = 1064 nm, 500 mJ, τ = 9 ns) with repletion rate of 10 Hz. The laser interaction on Al target (99.99%) under nitrogen gas atmosphere generate a plasma which is produced at room temperature; with variation in the pressure work from 0.53 Pa to 0.66 Pa matching with a applied laser fluence of 7 J/cm2.The films thickness measured by profilometer was 150 nm. The plasma generated was at different pressures was characterized by Optical Emission Spectroscopy (EOS). From emission spectra obtained ionic and atomic species were observed. The plume electronic temperature has been determined by assuming a local thermodynamic equilibrium of the emitting species. Finally the electronic temperature was cal
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Deposition pressure effect on chemical, morphological and optical properties of binary Al-nitrides  
Aluminum nitride films (AlN) were produced by Nd:YAG pulsed laser (PLD), with repetition rate of 10 Hz. The laser interaction on Al target under nitrogen gas atmosphere generates plasma which is produced at room temperature with variation in the pressure work from 0.39 Pa to 1.5 Pa thus producing different AlN films. In this sense the dependency of optical properties with the pressure of deposition was studied. The plasma generated at different pressures was characterized by optical emission spectroscopy (OES). Additionally ionic and atomic species from the emission spectra obtained were observed. The plume electronic temperature has been determined by assuming a local thermodynamic equilibrium of the emitting species. Finally the electronic temperature was calculated with Boltzmann plot from relative intensities of spectral lines. The morphology and composition of the films were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy analysis (XPS) and Raman Spectroscopy. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range from 400 nm to 900 nm. A clear dependence in morphological properties and optical properties, as a function of the applied deposition pressure, was found in this work which offers a novel application in optoelectronic industry.
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Correlation between optical, morphological and compositional properties of Aluminum Nitride thin films by Pulsed Laser Deposition  
AlN thin films were grown in a N2 atmosphere onto a Si/Si3N4 substrate by pulsed laser ablation. We have varied the substrate temperature for the thin film growth, using X-ray Reflectometry (XRR) analysis, we have characterized the thickness and density of the thin layer and the interface roughness from the X-ray reflectivity profiles. Experimental data showed that the root-mean-square roughness was in the range of 0.3 nm. X-ray photoelectron spectroscopy (XPS) was employed to characterize the chemical composition of the films. These measurements detected carbon and oxygen contamination at the surface. In the high-resolution X-ray photoelectron spectroscopy Al2p data, binding energies for Al-N and Al-O species were identified but no Al-Al species were present. In the N1s data, N-O species were not detected, but chemically bonded O was present in the films as Al-O species. Furthermore the value of optical energy gap, Eg was about 5.3 (± 0.1) eV. The composition varied with process conditions, and the nitrogen content decreased in AlN films processed above 500°C.
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