This document summarizes research on the effect of synthesis parameters on the structural properties of aluminum nitride (AlN) thin films deposited on metal substrates using DC sputtering.
Key findings include:
1) X-ray diffraction analysis showed the films had mixed cubic and hexagonal phases. Cubic phases were more prominent on copper substrates and increased with higher sputtering power and nitrogen gas flow.
2) Crystallite size, dislocation density, residual stress, and strain of the AlN films varied based on the sputtering power, gas ratio, and substrate material used. Optimal properties were observed for films deposited at 300W power and an Ar:N2 ratio of 14:6.
Effect of Adding Indium on Wetting Behavior, Microstructure and Physical Prop...Editor IJCATR
Effect of adding indium on microstructure, wetting process, thermal, electrical and mechanical properties of tin- zinc eutectic alloy have been investigated. Microstructure (started base line, lattice parameters, unit cell volume, crystal size and the shape of formed crystalline phases) and measured physical properties of tin- zinc eutectic alloy changed after adding different ratio of indium content. A little variation occurred in thermo-graph (Endo-thermal peaks) of Sn91Zn9 alloy after adding indium. The contact angle, melting temperature and specific heat of Sn91Zn9 alloy decreased after adding indium content. Also elastic modulus and internal friction values of Sn91Zn9 alloy decreased after adding indium content. But electrical resistivity and Vickers hardness values of Sn91Zn9 alloy increased after adding indium content. The SnZn9In5 alloy has adequate properties for solder applications.
An equiaxed, submicron grain size distribution was generated in an Al (0.1 wt.% Sc) alloy by
processing through equal channel angular pressing followed by a low temperature pre-
ageing heat treatment. The alloy was subsequently annealed for various times at 300, 350,
400 and 450° C for investigating the thermal stability of the deformation microstructure. It
was found that up to 400° C, the submicron grain structure coarsens slowly and uniformly by
a process of continuous recrystallization.
2018 khodan an-porous monoliths consisting of aluminum oxyhydroxide nanofibrilsAnatoleNKhodan
Abstract We present a study on the chemical and structural transformations in highly porous monolitic materials consisting of the nanofibrils of aluminum oxyhydroxides (NOA, Al2O3·nH2O) in the temperature range 20– 1700 °C. A remarkable property of the NOA material is the preservation of the monolithic state during annealing over the entire temperature range, although the density of the monolith increases from ~0.02 up to ~3 g/cm3, the total porosity decreases from 99.3 to 25% and remains open up to 4 h annealing at the temperature ~1300 °C. The physical parameters of NOA monoliths such as density, porosity, specific area were studied and a simple physical model describing these parameters as the function of the average size of NOA fibrils—the basic element of 3D structure—was proposed. The observed thermally induced changes in composition and structure of NOA were successfully described and two mechanisms of mass transport in NOA materials were revealed. (i) At moderate temperatures (T ≤ 800 °C), the mass transport occurs along a surface of amorphous single fibril, which results in a weak decrease of the length-to-diameter aspect ratio from the initial value ~24 till ~20; the corresponding NOA porosity change is also small: from initial ~99.5 to 98.5%. (ii) At high temperatures (T > 800 °C), the mass transport occurs in the volume of fibrils, that results in changes of fibrils shape to elliptical and strong decrease of the aspect ratio down to ≤ 2; the porosity of NOA decreases to 25%. These two regimes are characterized by activation energies of 28 and 61 kJ/mol respectively, and the transition temperature corresponds to the beginning of γ-phase crystallization at 870 °C.
Effect of Adding Indium on Wetting Behavior, Microstructure and Physical Prop...Editor IJCATR
Effect of adding indium on microstructure, wetting process, thermal, electrical and mechanical properties of tin- zinc eutectic alloy have been investigated. Microstructure (started base line, lattice parameters, unit cell volume, crystal size and the shape of formed crystalline phases) and measured physical properties of tin- zinc eutectic alloy changed after adding different ratio of indium content. A little variation occurred in thermo-graph (Endo-thermal peaks) of Sn91Zn9 alloy after adding indium. The contact angle, melting temperature and specific heat of Sn91Zn9 alloy decreased after adding indium content. Also elastic modulus and internal friction values of Sn91Zn9 alloy decreased after adding indium content. But electrical resistivity and Vickers hardness values of Sn91Zn9 alloy increased after adding indium content. The SnZn9In5 alloy has adequate properties for solder applications.
An equiaxed, submicron grain size distribution was generated in an Al (0.1 wt.% Sc) alloy by
processing through equal channel angular pressing followed by a low temperature pre-
ageing heat treatment. The alloy was subsequently annealed for various times at 300, 350,
400 and 450° C for investigating the thermal stability of the deformation microstructure. It
was found that up to 400° C, the submicron grain structure coarsens slowly and uniformly by
a process of continuous recrystallization.
2018 khodan an-porous monoliths consisting of aluminum oxyhydroxide nanofibrilsAnatoleNKhodan
Abstract We present a study on the chemical and structural transformations in highly porous monolitic materials consisting of the nanofibrils of aluminum oxyhydroxides (NOA, Al2O3·nH2O) in the temperature range 20– 1700 °C. A remarkable property of the NOA material is the preservation of the monolithic state during annealing over the entire temperature range, although the density of the monolith increases from ~0.02 up to ~3 g/cm3, the total porosity decreases from 99.3 to 25% and remains open up to 4 h annealing at the temperature ~1300 °C. The physical parameters of NOA monoliths such as density, porosity, specific area were studied and a simple physical model describing these parameters as the function of the average size of NOA fibrils—the basic element of 3D structure—was proposed. The observed thermally induced changes in composition and structure of NOA were successfully described and two mechanisms of mass transport in NOA materials were revealed. (i) At moderate temperatures (T ≤ 800 °C), the mass transport occurs along a surface of amorphous single fibril, which results in a weak decrease of the length-to-diameter aspect ratio from the initial value ~24 till ~20; the corresponding NOA porosity change is also small: from initial ~99.5 to 98.5%. (ii) At high temperatures (T > 800 °C), the mass transport occurs in the volume of fibrils, that results in changes of fibrils shape to elliptical and strong decrease of the aspect ratio down to ≤ 2; the porosity of NOA decreases to 25%. These two regimes are characterized by activation energies of 28 and 61 kJ/mol respectively, and the transition temperature corresponds to the beginning of γ-phase crystallization at 870 °C.
Aluminum doped cadmium selenide tin films of different compositions, (0.1-1.0 mol %) deposited by dip
coating method on cleaned glass substrates at room temperature. All the films are polycrystalline nature
having hexagonal structure. For all the films the preferred orientation is (100). Some other orientations like
(101), (110), (112) (202) (203) are also observed in the films. The values of interplanar distance, dislocation
density, microstrain, lattice parameters, volume of unit cell, number of crystallites per unit area and particle
size of the aluminum doped thin films were calculated and their variation with dopant concentration was
studied. Interplanar distance, intensity, lattice parameters, volume of unit cell and particle size increases up
to 0.25mol % of aluminum. Microstrain, dislocation density and number of crystallite per unit area decreases
up to 0.25mol % aluminum concentration
Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Graphene field-effect transistor simulation with TCAD on top-gate dielectric ...TELKOMNIKA JOURNAL
This paper presents the influence of top-gate dielectric material for graphene field-effect transistor (GFET) using TCAD simulation. Apart from silicon-based dielectric that is typically used for top-gate structure, other high-dielectric constant (high-k) dielectric materials namely aluminum oxide and hafnium oxide are also involved in the analysis deliberately to improve the electrical properties of the GFET. The unique GFET current-voltage characteristics against several top-gate dielectric thicknesses are also investigated to guide the wafer fabrication engineers during the process optimization stage. The improvement to critical electrical parameters of GFET in terms of higher saturation drain current and greater on/off current ratio shows that the use of high-k dielectric material with very thin oxide layer is absolutely necessary.
Microstructure, thermal, electrical and mechanical properties of penta Bi- Sn- Pb based alloys have been investigated. Matrix structure (Formed crystalline phases) and measured physical properties of Bi- Sn- Pb- In- X (X= Cd/or Zn) penta alloys changed with varying composition. The new penta fusible, Bi50Pb15Sn22Cd3In10, alloy has best properties such as high density, low melting point and friendly environmental, (reduced toxicity elements Pb and Cd by 40% and 75%, compared used alloys), for shielding blocks in mega-volt radiotherapy. The melting temperature of Bi50Pb15Sn22Cd3In10 alloy is ~58 ºC and it is density is 10.117 gm/cm3. The elastic modulus of Bi50Pb15Sn22Cd3In10 is 29.03 Gpa. Vickers hardness and internal friction values of Bi50Pb15Sn22Cd3In10 alloy are 9.72 Kg/mm2 and 0.085. The Bi50Pb15Sn22Cd3In10 alloy consists of rhombohedral Bi phase, tetragonal Sn phase, face centered cubic Pb phase, hexagonal Cd phase, face centered cubic In phase, Pb7Bi3 and SnBi intermetallic compounds.
Influence of phase transformation on the work hardening characteristics of Pb...iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Correlation between the Interface Width and the Adhesion Strength of Copper F...IOSRJAP
The present study has been conducted in order to determine the influence of negative bias voltage applied to substrate on adhesion of copper films deposited on carbon steel substrates. The adhesion strength has been evaluated by the scratch test. Coatings were deposited by a DC magnetron sputtering system. The substrates were firstly mechanically polished and then ion-etched by argon ions prior to deposition. Adhesion was found to increase with the bias voltage. The critical load had a value of 9.5 g for an unbiased substrate and reached 18.5 g for a bias voltage of 600 V. Equally important, the interface width, measured using Auger electron spectroscopy, increased as a function of the bias voltage. The width of the interface is related to the time of ion milling in the Auger spectrometer. The size of this width is obtained from the Auger elemental depth profiles through measuring the depth of the interface coating/substrate. The width had a value of 335 min with a bias of 600 V whereas it didn't exceed 180 min when the substrate was unbiased. Therefore, the effect of the bias voltage was to expand the interface because of the diffusion phenomenon and physical mixing of materials at the interface. Moreover, the critical load increased with the increase of the interface width.
Aluminum doped cadmium selenide tin films of different compositions, (0.1-1.0 mol %) deposited by dip
coating method on cleaned glass substrates at room temperature. All the films are polycrystalline nature
having hexagonal structure. For all the films the preferred orientation is (100). Some other orientations like
(101), (110), (112) (202) (203) are also observed in the films. The values of interplanar distance, dislocation
density, microstrain, lattice parameters, volume of unit cell, number of crystallites per unit area and particle
size of the aluminum doped thin films were calculated and their variation with dopant concentration was
studied. Interplanar distance, intensity, lattice parameters, volume of unit cell and particle size increases up
to 0.25mol % of aluminum. Microstrain, dislocation density and number of crystallite per unit area decreases
up to 0.25mol % aluminum concentration
Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Graphene field-effect transistor simulation with TCAD on top-gate dielectric ...TELKOMNIKA JOURNAL
This paper presents the influence of top-gate dielectric material for graphene field-effect transistor (GFET) using TCAD simulation. Apart from silicon-based dielectric that is typically used for top-gate structure, other high-dielectric constant (high-k) dielectric materials namely aluminum oxide and hafnium oxide are also involved in the analysis deliberately to improve the electrical properties of the GFET. The unique GFET current-voltage characteristics against several top-gate dielectric thicknesses are also investigated to guide the wafer fabrication engineers during the process optimization stage. The improvement to critical electrical parameters of GFET in terms of higher saturation drain current and greater on/off current ratio shows that the use of high-k dielectric material with very thin oxide layer is absolutely necessary.
Microstructure, thermal, electrical and mechanical properties of penta Bi- Sn- Pb based alloys have been investigated. Matrix structure (Formed crystalline phases) and measured physical properties of Bi- Sn- Pb- In- X (X= Cd/or Zn) penta alloys changed with varying composition. The new penta fusible, Bi50Pb15Sn22Cd3In10, alloy has best properties such as high density, low melting point and friendly environmental, (reduced toxicity elements Pb and Cd by 40% and 75%, compared used alloys), for shielding blocks in mega-volt radiotherapy. The melting temperature of Bi50Pb15Sn22Cd3In10 alloy is ~58 ºC and it is density is 10.117 gm/cm3. The elastic modulus of Bi50Pb15Sn22Cd3In10 is 29.03 Gpa. Vickers hardness and internal friction values of Bi50Pb15Sn22Cd3In10 alloy are 9.72 Kg/mm2 and 0.085. The Bi50Pb15Sn22Cd3In10 alloy consists of rhombohedral Bi phase, tetragonal Sn phase, face centered cubic Pb phase, hexagonal Cd phase, face centered cubic In phase, Pb7Bi3 and SnBi intermetallic compounds.
Influence of phase transformation on the work hardening characteristics of Pb...iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Correlation between the Interface Width and the Adhesion Strength of Copper F...IOSRJAP
The present study has been conducted in order to determine the influence of negative bias voltage applied to substrate on adhesion of copper films deposited on carbon steel substrates. The adhesion strength has been evaluated by the scratch test. Coatings were deposited by a DC magnetron sputtering system. The substrates were firstly mechanically polished and then ion-etched by argon ions prior to deposition. Adhesion was found to increase with the bias voltage. The critical load had a value of 9.5 g for an unbiased substrate and reached 18.5 g for a bias voltage of 600 V. Equally important, the interface width, measured using Auger electron spectroscopy, increased as a function of the bias voltage. The width of the interface is related to the time of ion milling in the Auger spectrometer. The size of this width is obtained from the Auger elemental depth profiles through measuring the depth of the interface coating/substrate. The width had a value of 335 min with a bias of 600 V whereas it didn't exceed 180 min when the substrate was unbiased. Therefore, the effect of the bias voltage was to expand the interface because of the diffusion phenomenon and physical mixing of materials at the interface. Moreover, the critical load increased with the increase of the interface width.
Krishnan - Energetic Condensation Growth of Nb films for SRF Acceleratorsthinfilmsworkshop
http://www.surfacetreatments.it/thinfilms
Energetic Condensation Growth of Nb films for SRF accelerators (Mahadevan Krishnan - 30')
Speaker: Mahadevan Krishnan - Alameda Applied Sciences Corporation | Duration: 30 min.
Abstract
AASC, Jefferson Lab and NSU conduct research into new SRF thin-film coatings by first characterizing the materials properties such as morphology, grain size, crystalline structure, defects, and impurities, then measuring properties such as Tc and RRR and following this with ‘in-cavity’ RF measurements of the Surface Impedance of the films at cryogenic temperatures. These progressive steps are essential to the eventual design of SRF accelerator structures and to measure Q-slope and other performance parameters at high fields.
This paper describes recent results from pure Nb thin-films grown on a-plane and c-plane sapphire, MgO as well as on amorphous substrates. Substrate preparation is shown to be critical to good electrical properties of the film. The sapphire and MgO substrates were heated up to 700 deg C and subsequently coated at 300, 500 and 700 deg C. Film thickness was varied from ~0.25µm up to >3µm. RRR and Tc were measured. The XRD data yielded pole figures, intensity vs. 2-θ and intensity vs. φ plots. These data were complemented by EBSD and SEM images. RRR values ranging from ~10 up to ~333 have been measured and correlated with the XRD data. Good crystallinity is associated with high RRR. Single crystalline (110) epitaxial layers of Nb films are grown well on a-plane sapphire substrates at different temperatures. Nb films have also been grown on Cu substrates, as well as on MgO and borosilicate substrates. The significance of crystalline structure observed on amorphous substrates is discussed in light of its implications for future, lower-cost SRF cavities.
Effect of Adding Indium on Wetting Behavior, Microstructure and Physical Prop...Editor IJCATR
Effect of adding indium on microstructure, wetting process, thermal, electrical and mechanical properties of tin- zinc eutectic alloy
have been investigated. Microstructure (started base line, lattice parameters, unit cell volume, crystal size and the shape of formed crystalline
phases) and measured physical properties of tin- zinc eutectic alloy changed after adding different ratio of indium content. A little variation
occurred in thermo-graph (Endo-thermal peaks) of Sn91Zn9 alloy after adding indium. The contact angle, melting temperature and specific heat of
Sn91Zn9 alloy decreased after adding indium content. Also elastic modulus and internal friction values of Sn91Zn9 alloy decreased after adding
indium content. But electrical resistivity and Vickers hardness values of Sn91Zn9 alloy increased after adding indium content. The SnZn9In5 alloy
has adequate properties for solder applications.
Different Topics Dealing With Sputtering Of Cu, Ni And Cu-Ni Targets In Diffe...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Un doped and doped with Al ZnS thin Films have been fabricated by vacuum evaporation
technique under the vacuum of 10-5 Torr on glass substrate at room temperature and with different
ratio of Al concentration of thickness (0.8µm). The optical properties were revealed by UV-Visible
transmittance spectra and the band gap energy was determined. Transmission spectra indicate a high
transmission coefficient (¨95%). The results showed that films have direct optical transition, and the
values of energy gap were found to decrease with doping concentrations. Also the optical constants
such as absorption coefficient, refractive index, extinction coefficient and dielectric constant have
been calculated. The effect of doping concentration on the electrical properties has been studied
Annealing and Microstructural Characterization of Tin-Oxide Based Thick Film ...Anis Rahman
Abstract. The sheet resistance of tin oxide based thick-film resistors exhibits two regions of temperature dependence,
described by hopping (23°C-200°C) and diffusion mechanisms (200°C-350°C), respectively.
Annealing these samples causes the sheet resistance to increase in both regions. In the post-annealed samples,
the hopping conduction range is extended by 50°C (23°C-250°C) while the hopping parameter, To, is decreased by
more than 50%. The activation energy of diffusion (0.60 eV) is the same for both pre- and post annealed samples, but
the magnitude of resistance in the diffusion controlled region is increased significantly as a result of annealing. These
changes are explained in terms of a net decrease in the concentration of tin ions in the glass matrix. From a careful
microstructural study it was found that a conduction path composed of tin-oxide grains or their clusters in contact
with each other does not exist in the present system. HREM micrographs showed the presence of nanocrystalline
tin-oxide particles in the glass phase separating the tin-oxide grain clusters. Estimated average separation between
the nanocrystals in 4 nm, consistent with a variable-range hopping conduction via the dissolved tin ions in the glass
matrix.
Combining forecast from different models has shown to perform better than single forecast in most time series. To improve the quality of forecast we can go for combining forecast. We study the effect of decomposing a series into multiple components and performing forecasts on each component separately... The original series is decomposed into trend, seasonality and an irregular component for each series. The statistical methods such as ARIMA, Holt-Winter have been used to forecast these components. In this paper we focus on how the best models of one series can be applied to similar frequency pattern series for forecasting using association mining. The proposed method forecasted value has been compared with Holt Winter method and shown that the results are better than Holt Winter method
Independent Component Analysis for Filtering Airwaves in Seabed Logging Appli...IJASCSE
Marine controlled source electromagnetic (CSEM) sensing method used for the detection of hydrocarbons based reservoirs in seabed logging application does not perform well due to the presence of the airwaves (or sea-surface). These airwaves interfere with the signal from the subsurface, as a result masks the receiver response at larger offsets. The task is to identify these air waves and the way they interact, and to filter them out. In this paper, a popular method for counteracting with the above stated problem scenario is Independent Component Analysis (ICA). Independent component analysis (ICA) is a statistical method for transforming an observed multidimensional or multivariate dataset into its constituent components (sources) that are statistically as independent from each other as possible. ICA-type de-convolution algorithm that is FASTICA is considered for mixed signals de-convolution and considered convenient depending upon the nature of the source and noise model. The results from the FASTICA algorithm are shown and evaluated. In this paper, we present the FASTICA algorithm for the seabed logging application.
Enhanced Performance of Search Engine with Multitype Feature Co-Selection of ...IJASCSE
Information world meet many confronts nowadays and one such, is data retrieval from a multidimensional and heterogeneous data set. Han & et al carried out a trail for the mentioned challenge. A novel feature co-selection for web document clustering is proposed by them, which is called Multitype Features Co-selection for Clustering (MFCC). MFCC uses intermediate clustering results in one type of feature space to help the selection in other types of feature spaces. It reduces effectively of the noise introduced by “pseudoclass” and further improves clustering performance. This efficiency also can be used in data retrieval, by implementing the MFCC algorithm in ranking algorithm of Search Engine technique. The proposed work is to apply the MFCC algorithm in search engine architecture. Such that the information retrieves from the dataset is retrieved effectively and shows the relevant retrieval.
Improving Utilization of Infrastructure CloudIJASCSE
A key advantage of Infrastructure-as-a-Service (IaaS) cloud is providing users on-demand access to resources. However, to provide on-demand access, cloud providers must either significantly overprovision their infrastructure (or pay a high price for operating resources with low utilization) or reject a large proportion of user requests (in which case the access is no longer on-demand). At the same time, not all users require truly on-demand access to resources. Many applications and workflows are designed for recoverable systems where interruptions in service are expected. For instance, many scientists utilize High Throughput Computing (HTC)-enabled resources, such as Condor, where jobs are dispatched to available resources and terminated when the resource is no longer available. We propose a cloud infrastructure that combines on-demand allocation of resources with opportunistic provisioning of cycles from idle cloud nodes to other processes by deploying backfill Virtual Machines (VMs).
Four Side Distance: A New Fourier Shape SignatureIJASCSE
Shape is one of the main features in content based image retrieval (CBIR). This paper proposes a new shape signature. In this technique, features of each shape are extracted based on four sides of the rectangle that covers the shape. The proposed technique is Fourier based and it is invariant to translation, scaling and rotation. The retrieval performance between some commonly used Fourier based signatures and the proposed four sides distance (FSD) signature has been tested using MPEG-7 database. Experimental results are shown that the FSD signature has better performance compared with those signatures.
Theoretical study of axially compressed Cold Formed Steel SectionsIJASCSE
Conceptual and finite element analysis oriented design of cold formed steel columns are presented in this paper. Total four 1 meter channel lipped section with thickness of 1, 1.2, 1.5 and 1.9 are tested. All columns were tested under a pure axial load, Conceptual design results are compared with finite element analysis for axially loaded compression members. The results provide useful information regarding allowable load estimation of cold formed steel column section. Based on the results, design recommendations were proposed. The proposed design approach is recommended for the design of complex shape of cold formed steel section, where design rules are not available in standards.
Improved Performance of Unsupervised Method by Renovated K-MeansIJASCSE
Clustering is a separation of data into groups of similar objects. Every group called cluster consists of objects that are similar to one another and dissimilar to objects of other groups. In this paper, the K-Means algorithm is implemented by three distance functions and to identify the optimal distance function for clustering methods. The proposed K-Means algorithm is compared with K-Means, Static Weighted K-Means (SWK-Means) and Dynamic Weighted K-Means (DWK-Means) algorithm by using Davis Bouldin index, Execution Time and Iteration count methods. Experimental results show that the proposed K-Means algorithm performed better on Iris and Wine dataset when compared with other three clustering methods.
A Study on the Effectiveness of Computer Games in Teaching and LearningIJASCSE
Games, especially computer games are becoming one of the tools of education. Nowadays, the usage of computer games as an educational tool has become a worldwide trend. An early assumption suggests that since the appeal of computer games can engage interest and motivation, thus it is a wise step to use computer games for the purpose of educating. This is because students often get bored with the learning process; therefore we need to find creative ways to teach them. Instead of the usual, dull lesson in class, educators are trying out new ways to attract the interest of students to focus the lessons and thus increase their understanding, with one of it using computer games. A lot of papers supported the idea of computer games being effective as an aid for students. Educators alike also agreed that it is one of the ways to gain students interest in their lessons. Before coming to the ultimate conclusion that computer games are a good choice, first of all we need to study carefully the effectiveness of using computer games as an educational medium. This paper aims to study the effectiveness of computer games in learning among students. Issues on the integration of computer games in formal education are and the current status of educational gaming in learning were reviewed in this paper. We focused on higher learning context which is for university students.
Clustering Based Lifetime Maximizing Aggregation Tree for Wireless Sensor Net...IJASCSE
Energy efficiency is the most important issue in all facets of wireless sensor networks (WSNs) operations because of the limited and non-replenish able energy supply. The data aggregation mechanism is one of the possible solutions to prolong the lifetime of sensor nodes and on the other hand it also helps in eliminating the data redundancy and improving the accuracy of information gathering, is essential for WSNs. In this paper we propose a Clustering based lifetime maximizing aggregation tree (CLMAT) in which we create aggregation tree which aim to reduce energy consumption.
Design Equation for CFRP strengthened Cold Formed Steel Channel Column SectionsIJASCSE
Carbon fiber reinforce polymer (CFRP) strengthened steel structural members such as beams, columns and bridge decks have become progressively popular as a result of extensive studies in this field. This paper presents the recent developments in CFRP strengthened steel channel sections and proposed conceptual model for prediction of column strength under pure axial loads per Indian standards-IS801-1975 and Euro code 3(EC 3)standards . Eight cold-formed steel circular lipped channel section columns with externally bonded CFRP were tested under pure axial compression. IS801/EC3 proposed methods were compared with experimental results. The results show that the proposed method gives around 11 percent increase in strength due to CFRP.
A Study on Thermal behavior of Nano film as thermal interface layerIJASCSE
Increase in thermal design power and re-duce in manufacturing cost of the processor chip has pushes the need for high performance and durable test fixture design in future. Test fixture with efficient themal management has lowest resistance possible to maintain the accuracy of the device temperature when it makes contact with processor chip’s silicon during test. High thermal conductivity and mechanical relia-bility of text fixures are desired for high volume test environment. Nano film materials such as Aluminum Titanium Nitride (AlTiN), Titanium carbide (TiC), Ti-tanium on Titanium nitride (Ti on TiN), Titanium ni-tride on Titanium (TiN on Ti) and Aluminum(III) Ox-ide (Al2O3) are coated over copper substrates by Fil-tered Cathodic Vacuum Arc (FCVA) deposition method and tested for their thermal conductivity behavior for high volume test (HVM) environment. Thermal con-ductivity of the prepared films is tested by using the ASTM 5470 Thermal Interface Material (TIM) Tester. Titanium on Titanium nitride (Ti on TiN) and Alumi-num (III) Oxide (Al2O3) observed with highest thermal conductivity of 117.68 W/mk and 128.34 W/mk respec-tively among the prepared nano thin films. Thickness of the film and stack configuration influenced the thermal conductivity of the prepared film.
Investigation of Integrated Rectangular SIW Filter and Rectangular Microstrip...IJASCSE
This paper presents an investigation based on the resonant circuit approach to characterize an integrated microwave filter and antenna from a lumped element prototype. This approach is used to design an integrated filter and antenna to reduce the overall size of the physical dimensions of the RF/microwave front-end subsystem. This study focuses on the integration of a rectangular Substrate Integrated Waveguide (SIW) filter with a rectangular microstrip patch antenna to produce a filtering and radiating element in a single device. The physical layouts of the SIW filter and rectangular microstrip patch antenna based on single- and dual-mode will be developed. To prove the concept, the integrated microwave filter and antenna at a center frequency of 2 GHz is demonstrated and validated through simulation and laboratory experiments. The experimental performance yielded promising results that were in good agreement with the simulated results. This study is beneficial for microwave systems, given that the reduction of the complexity of design and physical dimension as well as cost are important for applications such as base stations and multiplexers in wireless communication systems.
Analysis and Design of Lead Salt PbSe/PbSrSe Single Quantum Well In the Infra...IJASCSE
There is a considerable interest in studying the energy spectrum changes due to the non parabolic energy band structure in nano structures and nano material semiconductors. Most material systems have parabolic band structures at the band edge, however away from the band edge the bands are strongly non parabolic. Other material systems are strongly parabolic at the band edge such as IV-VI lead salt semiconductors. A theoretical model was developed to conduct this study on PbSe/Pb 0.934 Sr0.066 Se nanostructure system in the infrared region. Moreover, we studied the effects of four temperatures on the analysis and design of this system. It will be shown that the total losses for the system are higher than the modal gain values for lasing to occur and multiple quantum well structures are a better design choice.
Stable and Reliable Route Identification Scheme for Efficient DSR Route Cache...
An effect of synthesis parameters on structural properties of AlN thin films deposited on metal substrates
1. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
An effect of synthesis parameters on structural
properties of AlN thin films deposited on metal
substrates
S. Shanmugan, P. Anithambigai, D. Mutharasu I.Abdul Razak
Nano Optoelectronics Research Laboratory, X-ray Crystallography Group,
School of Physics, University Sains Malaysia, School of Physics, University Sains Malaysia,
11800 Minden, Penang, Malaysia 11800 Minden, Penang, Malaysia
sputtered compounds such as stainless steel–carbon (SS–C)
[2,3] and Al–N cermet solar coatings [4-7]. Hence Mo -
Abstract— AlN thin film was prepared over different Al2O3 is considered more expensive than SS–C and Al–N
metal substrates using DC sputtering at various cermet solar coatings which are also produced using a
sputtering parameters. The XRD spectra revealed the commercial-scale cylindrical dc sputtering coater. Among
presence of mixed (cubic and hexagonal) phases for all these, Aluminum nitride (AlN) has generated much interest
samples other than samples prepared at 300W with due to its unique properties of wide band gap of 6.2 eV,
Ar:N2 gas ratio of 14:6. The intensities of cubic phases high thermal conductivity (320Wm−1 K−1) [8], low thermal
observed at copper (Cu) substrates increased drastically expansion coefficient, high chemical and thermal stabilities,
with high sputtering power and N2 gas flow. Low high breakdown dielectric strength, and high surface
intensive peak was observed at gas mixer ratio of 14:6. acoustic wave velocity [9-11]. So far, a variety of deposition
N2 flow and sputtering power influenced the crystallinity methods have been reported for AlN synthesis such as
of the AlN thin film with respect to the substrates. Mixed reactive sputtering [12], reactive evaporation [13] metal-
residual stress (compressive and tensile) was observed organic chemical vapor deposition (MOCVD) [14], laser-
for all samples and high values were observed at 300W molecular beam epitaxy [15], pulsed laser deposition (PLD)
sputtering power at low N2 gas flow. Crystallite size of [16], arc discharge method [17], and chloride-assisted
AlN thin film varied with respect to sputtering power, chemical vapor deposition [18]. Among these, reactive
gas flow ratio and also substrates. AlN thin film sputtering is relatively good and low cost method for the
prepared at 250 W showed high dislocation density at preparation of AlN thin films. The growth condition is an
high N2 gas flow ratio. Atomic force microscope results important which influences the structural and optical
showed rough surface for AlN thin film coated over Al properties of the film considerably.
substrates and increased high value was observed at high Few research reports showed the influence of
N2 gas flow ratio. The particle size of the AlN thin films deposition parameters on the orientation of the AlN films, in
increased with N2 gas flow increased with respect to which a general guideline promoting a well c-axis oriented
sputtering power and high value was observed with Al thin film was reported. The sputtering pressure plays an
substrates. important role in the growth of preferred AlN and reported
that the preferred orientation of the AlN film changed from
Keywords- AlN; thin film; structural parameters; metal (1 0 0) to (0 0 0 2) with decreased sputtering pressure [19–
substrates; particle size 23] and also reported in a decrease of the FWHM of (0 0 0
2) rocking curve [24]. However, it is necessary to
I. INTRODUCTION understand the influence of other synthesis parameter on the
Since the high thermal stability of Mo - Al2O3 cermet film properties. Iriarte et. al. reported the influence of
at high operating temperature in vacuum (450 -500 ºC), it is different substrates on the properties of c-axis oriented AlN
desirable for solar collector tubes for solar thermal electricity thin films [25]. Based on the application, AlN films have
applications. Even though, solar absorptance of 0.96 with been deposited on various substrates such as tungsten [26],
emittance of 0.16 was observed, the deposition rate is low sapphire [27] and diamond [28] substrates and reported their
[1], cost of deposition using planar magnetron sputtering is properties. This work focuses on the deposition of thin AlN
much higher when compared to reactively films on different metal substrates (Cu, Al) and study the
influence of growth condition such as sputtering power, gas
flow rate and also substrates. The selection of substrates is
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2. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
based on the material used for solar thermal as well as In addition, a new intensive (200) peak is also observed at
electrical applications. The structural properties such as 42.86 º instead of (200) peak observed at 45.36º when the
crystallite size, dislocation density, internal stress, etc., of all film coated at Ar:N2 gas ratio of 13:7.
prepared samples are also reported here.
II. EXPERIMENTAL METHODS
AlN thin films were deposited on different metal
substrates (Al and Cu) using Al (99.99% purity) target (3
inch in diameter and 4 mm in thickness) by DC sputtering
(Edwards make, Model-Auto 500). The chamber was
initially pumped down to high vacuum 8.2 x 10-6 mbar. All
AlN thin films were coated at chamber pressure of 8.2 x 10 -
3
. High pure Ar (99.999%) and N2 (99.999%) were used for
AlN coatings. All thin films were coated for three different
Ar and N2 gas mixture ratio (16:4 – 80:20, 14:6 - 70:30 and
13:7 – 65:35) at two different sputtering power (250 and 300
W). The total flow rate is maintained as 20 sccm. The
substrates were cleaned by rinsing in ultrasonic bath of
acetone and isopropyl alcohol. All AlN thin films were
coated at room temperature and the thickness of the film was
800 nm measured for all prepared films by digital thickness
monitor. The deposition rate was varied form 0.42 Å / sec to
1.5 Å / sec. In order to remove the surface oxidation of the
target, pre-sputtering was carried out for 5 min before
starting deposition at Ar pressure of 3.2 x 10 -3. To get the
uniform thickness, rotary drive system was used and 25
RPM was fixed for all AlN film coatings. The distance
between the substrates to target was fixed as 7 cm for all
depositions.
The crystalline nature of the as-grown AlN thin films
for all samples was investigated by using a high resolution
X-ray diffraction (HRXRD, X’pert-PRO, Philips,
Netherlands). A CuKα (λ = 1.54056 Å) source was used,
with a scanning range between 2θ = 32° and 70°. This range
has been selected because most of AlN peaks were observed
between this ranges. The surface morphology of the
prepared samples was tested by the atomic force microscope Figure 1. XRD spectra of AlN thin film prepared at 250 W on various
substrates and gas flow ratio
(AFM) and the results are reported here.
It is also observed that cubic phase are nominated but few
III. RESULTS AND DISCUSSION
hexagonal phases are also exist along with cubic phases.
A. Peak Intensity and Position Analysis Moreover, the (200) peak position shift towards lower 2θ as
the N2 gas ratio increases. But it is also noticed that the peak
The X-ray diffraction studies for all prepared thin films related to cubic phase observed at 39.02 º disappear and new
are carried out and observed as mixed phases (cubic and hexagonal phases are indexed in AlN thin film prepared at
hexagonal) with respect to the substrates and also sputtering gas ratio of 13:7. On consideration of Al substrates,
parameters. The XRD spectra show in Fig. 1 reveals the hexagonal phases are dominated one than cubical phase. In
diffracted profile of AlN thin film prepared at 250 W in addition, the intensity of peaks decreases as the N 2 gas flow
different gas ratio. As observed at 200W, the Cu substrates increases ie AlN thin film prepared at 16:4 gas ratio shows
supports the growth of (200) oriented Cubic AlN. But the higher intensity than prepared at 13:7 gas ratio. The cubic
intensities of the peak are different from the film deposited phase also observed on this Al substrates and their intensity
at 200W. As the N2 flow rate increases, the intensity of (200) decreases as the N2 flow rate increases. It could also be
oriented phase decreases and hexagonal phase starts to grow. observed that the peak position also shifted towards higher
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3. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
2θ as with N2 gas flow increases with respective to observed gas flow. The peak shifting from lower 2θ to higher 2θ
phases. Overall the crystal orientation as well as the could also be observed for higher N2 flow. Moreover,
crystallinity of the AlN films for various sputtering unidentified peaks are also observed which are not related to
parameters depends on the substrates used [29]. Fig. 2 shows the respective elements or compounds. This may arise as a
the XRD spectra of AlN thin film prepared at 300 W for result of impurity from the substrates. Moreover, a drastic
different gas mixture ratio and observed that no cubic increment on the intensity of hexagonal peak observed at 2θ
= 65.08º is also noticed for the AlN thin film coated at 14:6
ratio gas flow. Few cubic phases in addition to the
hexagonal phase are also observed when AlN thin film
prepared at gas mixed ratio of 13:7. In this case, cubic phase
are dominated and hexagonal are suppressed as a result of
higher N2 flow (13:7). Moreover, most of cubic phases exist
with Cu substrates with respect to sputtering power and N 2
gas flow ratio. Since, cubic copper substrates enhance the
growth of cubic (2 0 0) oriented AlN than h (1 0 3) phase of
AlN, mismatch between cubic Cu and cubic AlN thin film
are very less and hence suppress of hexagonal AlN growth
is observed on Cu substrates [30]. From Fig. 1 and Fig. 2,
all samples show very low intensity of (1 0 0) oriented peak
when compared to (1 0 3) oriented peak for various
sputtering power and N2 gas flow ratio which exhibit the
synthesized film is c-axis normal to the substrate [31].
B. Structural Parameter Analysis
The crystallite size (D) was calculated using the Debye
Scherer formula [32] from the full width at half-maximum
(w) measurements:
D = 0.94λ / w cos θ (1)
The crystallite size of all AlN thin film samples are
calculated and the observed results for the film prepared at
250 W are plotted in Fig. 3(a) and it reveals that the
crystallite size increases for the film prepared over Cu
substrates and decreases for Al substrates as N2 flow ratio
Figure 2. XRD spectra of AlN thin film prepared at 300 W on various increases. Moreover, high N2 flow does not support on the
substrates and gas flow ratio increase in crystallite size for AlN thin film coated on Cu
substrates. Fig. 3(b) shows the results of AlN thin film
phases are identified from AlN thin film coated on Cu prepared at 300 W and reveals that the same behavior could
substrates at gas mixture ratio of 14:6. The observed be observed as the crystallite size increases with N2 gas flow
intensity of the hexagonal peaks is low at this gas mixture ratio increases as observed at 250 W.
(14:6) compared to other gas mixture ratio for both Al and
Cu substrates. The intensity reduction and peak shift are also It is also noticed that the increasing behavior is only
could be observed as the N2 gas flow increases for hexagonal for N2 flow upto 14:6 ratio and decreases noticeably for
phase irrespective to substrates. From the Fig. 2, the indexed further increase of N2 flow.
peaks for AlN on Cu substrates at gas mixture ratio of 13:7
are same as the peaks observed from AlN thin film coated From Fig. 3, high value in crystallite size could be
over Cu substrates at gas mixture ratio of 16:4 but the observed for AlN thin film coated over Cu substrates
intensity of peak observed at 45.50º varies as high for Cu prepared at 300 W sputtering power.
substrates prepared with gas mixture ratio of 13:7. On
considering the Al substrates, hexagonal phases are
dominated and few cubic phase are observed at low and high
N2 gas mixture ratio. A drastic increment on the intensity of
(200) oriented peaks could be observed as with 13:7 ratio
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4. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
3(a)
4(a)
3(b) 4(b)
Figure 3 Crystallite size of AlN thin film prepared at (a) 250 W and (b) 300 Figure 4 Dislocation density of AlN thin film prepared at (a) 250 W and (b)
W sputtering power with various gas flow ratio. 300 W sputtering power with various gas flow ratio.
Also, the high sputtering power helps to improve the
crystallite size when AlN thin film coated over Al substrates. Fig. 4(a) shows the results of AlN thin film prepared at
In addition to this, the dislocation density (δ), defined as the 250 W and explains that an increasing manner in dislocation
length of dislocation lines per unit volume of the crystal, was density is observed for Al substrates as with N 2 flow
evaluated from the relation [33] and the observed results are increases.
plotted in Fig. 4(a) and (b).
Even though, high value is observed for AlN prepared
δ = 1 / D2 (2) over Cu substrates at 250 W power. But very low value in
dislocation density could be observed for AlN thin film
The strain (ε) was calculated from formula prepared at 14:6 for both substrates (Cu and Al) when
prepared at 300 W (see Fig. 4(b)).
ε = w cos θ / 4 (3)
The strain developed during the deposition of AlN thin
films over different surfaces are calculated and the observed
results are plotted in Fig. 5(a) and (b). As observed for
dislocation density, very low value of strain is observed for
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5. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
300 W for both substrates and the strain increases as the N 2
gas flow increases when the sputtering carried out at 250 W
power for AlN on Al substrates. Noticeable decrease in strain value is observed for AlN thin
film prepared over both substrates at 300 W as the N 2 flow
increases upto Ar:N2 - 14:6 ratio. From Fig. 5, substrates
and sputtering power influence on increasing the strain
value noticeably at high N2 gas flow ratio.
The internal stress (σ) in the deposited film is
calculated using the relation
σ = - E (da - do) / (2doY) (4)
where do and da are the d spacing of bulk and thin film
forms respectively [34]. E and Y are the Young’s modulus
and Poisson’s ratio of AlN respectively. The Young’s
modulus and Poisson’s ratio of AlN are E = 308 GPa [35]
5(a) and Y = 0.29 [36] respectively.
The structural parameters are measured from the XRD
spectra and given in Table 1 and Table 2. Table 1 shows the
results observed form the AlN thin film samples prepared at
300 W at various Ar and N2 gas ratio. From (3), the nature
of stress applied during the growth of crystal could be
identified by the sign of the observed value. If the observed
value is positive, it represents the compressive stress and if
it is negative, the tensile stress is applied during the growth
process.
5(b)
Figure 5 Variation in strain during the preparation of AlN thin film at (a)
250 W and (b) 300 W sputtering power with various gas flow ratio.
TABLE I. STRUCTURAL PROPERTIES OF AlN THIN FILM PREPARED OVER DIFFERENT METAL SUBSTRATE
AT 250 W FOR DIFFERENT GAS FLOW RATIO
Gas ratio Substrates Obs. 2θ Std. 2θ Obs. d Std. d Hkl FWHM Residual stress JCPDS No.
38.98 39.42 2.273 2.284 c111 0.092 0.199289 650841
Cu 45.34 45.84 1.984 1.978 c200 0.11 -0.12552 650841
16:4 66.04 66.06 1.425 1.413 h103 0.118 -0.35142 760702
40.29 39.61 2.255 2.2736 c111 0.069 0.338521 882250
Al 58.25 58.86 1.581 1.5675 h110 0.089 -0.35638 700354
69.57 69.78 1.371 1.3523 h200 0.102 -0.57221 893446
39.02 39.42 2.275 2.284 c111 0.023 0.163054 650841
Cu 45.36 45.84 1.983 1.978 c200 0.095 -0.1046 650841
14:6 66.06 66.06 1.415 1.413 h103 0.084 -0.05857 760702
40.33 39.61 2.254 2.2736 c111 0.177 0.356721 882250
Al 58.29 58.86 1.582 1.5675 h110 0.084 -0.38278 700354
69.65 69.78 1.376 1.3523 h200 0.102 -0.72521 893446
33.57 33.09 2.693 2.7046 h100 0.063 0.177477 893446
37.41 37.96 2.377 2.3685 h101 0.278 -0.1485 653409
Cu 38.45 38.26 2.341 2.3502 h101 0.197 0.161983 882360
42.86 41.81 2.089 2.159 c200 0.072 1.341627 871053
13:7 44.79 45.84 1.992 1.978 c200 0.218 -0.29288 650841
49.98 49.86 1.811 1.8273 h102 0.054 0.369117 653409
65.55 65.89 1.427 1.4164 h103 0.225 -0.30968 893446
37.88 37.96 2.376 2.3685 h101 0.257 -0.13103 653409
Al 40.25 39.61 2.256 2.2736 c111 0.095 0.320321 882250
58.21 58.86 1.582 1.5675 h110 0.126 -0.38278 700354
69.55 69.78 1.379 1.3523 h200 0.115 -0.817 893446
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6. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
TABLE II. STRUCTURAL PROPERTIES OF AlN THIN FILM PREPARED OVER DIFFERENT METAL SUBSTRATE
AT 300 W FOR DIFFERENT GAS FLOW RATIO
Gas Obs. Std. 2θ Obs. d Std. d hkl FWHM Residual stress JCPDS No.
ratio 2θ
16:4 Cu 39.03 39.42 2.3046 2.284 c111 0.088 -0.37321 650841
45.31 45.84 1.99622 1.978 c200 0.107 -0.38116 650841
66.06 66.06 1.4126 1.4033 h103 0.104 -0.27423 760702
Al 38.50 38.26 2.3350 2.3502 h101 0.082 0.267624 882360
40.25 39.61 2.2384 2.2736 c111 0.079 0.276641 882250
58.22 58.86 1.5835 1.5675 h110 0.092 -0.42238 700354
65.31 65.89 1.4352 1.4164 h103 0.06 -0.54924 893446
69.54 69.78 1.3504 1.3523 h200 0.102 0.058139 893446
14:6 Cu 33.04 33.09 2.7099 2.7046 h100 0.056 -0.08109 893556
59.16 59.12 1.5724 1.5615 h110 0.021 -0.28885 893446
Al 33.14 33.09 2.70996 2.7046 h100 0.063 -0.08201 893556
38.50 38.26 2.3167 2.3502 h101 0.027 0.589829 882360
65.08 65.89 1.4233 1.4164 h103 0.052 -0.20158 893446
13:7 Cu 39.19 39.42 2.3056 2.284 c111 0.202 -0.39133 650841
45.50 45.84 1.925 1.978 c200 0.123 1.108756 650841
66.18 66.06 1.4126 1.4033 h103 0.081 -0.27423 760702
Al 33.28 33.24 2.6892 2.6933 h101 0.108 0.062992 653409
38.59 38.26 2.3358 2.3502 h101 0.202 0.253539 882360
40.31 39.61 2.2384 2.2736 c111 0.079 0.640641 882250
58.29 58.86 1.5835 1.5675 h110 0.092 -0.42238 700354
65.20 65.89 1.4352 1.4164 h103 0.06 -0.54924 653409
69.61 69.78 1.3511 1.3466 h200 0.084 -0.13828 653409
From Table 1, tensile stress could be observed mostly Fig. 6 (a-f) shows the 3D surface morphology of AlN coated
for AlN thin film coated over Cu substrates and the applied Cu and Al substrates prepared at 300 W at various gas flow
tensile stress decreases as the N2 gas flow increases for Cu ratio. The first row (Fig. a, b and c) and second row show
substrates. Moreover, compressive stress is also observed the images of AlN thin film coated over Cu and Al
with Cu substrates at high N2 flow ratio. But AlN thin film substrates respectively. First, second and third columns
prepared over Al substrates shows compressive nature of show the results of various gas flow ratio such as 16:4, 14:6
stress at high N2 gas flow ratio. and 13:7 ratio respectively. It reveals that the surface
morphology of AlN thin film reflects the surface of metal
Table 2 shows the structural properties of AlN thin substrates as smooth surface for AlN on Cu substrates than
film prepared at 250 W by varying the Ar and N 2 gas flow Al substrates. The same observation is also observed for
ratio. For applied stress based on equation (4), mixed stress AlN thin films prepared at 250 W (see Fig. 7 (a-f)). In order
(compressive and tensile) could be observed for all samples to understand in detail, the surface roughness and the
irrespective to the N2 gas flow. High value of compressive particle size of prepared AlN thin film for various synthesis
stress is observed for (200) oriented cubic phase of AlN parameters are recorded and the observed results are
prepared at Cu substrates. Moreover, the applied stress tabulated in Table 3. It clearly indicates that the roughness
increases as with N2 gas flow increases for AlN thin film of the prepared film is low for AlN coated over Cu
coated over Al substrates. substrates than Al substrates. It could be seen that the
Meantime, the stress shows decreasing manner as with roughness is observed as high for 300 W powers at high N2
N2 gas flow decreases for Cu substrates. Overall, the applied flow (13:7).
stress is observed as low for AlN thin film prepared over Cu
substrates at low N2 flow ratio.
C. AFM - Surface Properties
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7. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
(a) (b) (c)
(d) (e) (f)
Figure 6 AFM images of AlN thin film prepared at 300 W sputtering power (Row 1 – Cu substrate and Row 2 – Al substrate, Column (a & d)
16:4, (b and e) 14:6 and (c and f) 13:7)
(a) (b) (c)
(d) (e) (f)
Figure 7 AFM images of AlN thin film prepared at 250 W sputtering power (Row 1 – Cu substrate and Row 2 – Al substrate, Column (a & d)
16:4, (b & e) 14:6 and (c & f) 13:7)
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8. Dec. 31 IJASCSE, VOL 1, ISSUE 4, 2012
High value is observed for Al substrates as 98 nm. power and gas flow influenced the change in particle size
Noticeable results are observed with Cu substrates as the with respect to metal substrates.
roughness decreases as the sputtering power increases from
250 to 300 W irrespective to the gas flow ratio. This may be ACKNOWLEDGMENT
attributed to the influence of applied stress during the growth
of AlN on Cu substrates at this N2 flow rates. In addition, the The authors would like to thank the Nano
particle size of the AlN thin film samples are also measured Optoelectronics Research Laboratory in School of Physics
by processing the AFM image and given in Table 4. It shows where all AlN thin film samples were synthesized by using
that very big particles (546 nm) are observed for high N 2 DC sputtering system and the XRD lab for providing the
flow at 250 W power. From Table 4, an increment in particle crystallographic analysis facilities.
size for applied sputtering power could be observed as the
N2 gas flow increases.
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