Top PDF Aluminum nitride deposition using an AlN/Al sputter cycle technique

Aluminum nitride deposition using an AlN/Al sputter cycle technique

Aluminum nitride deposition using an AlN/Al sputter cycle technique

A method for forming thin films of dielectric material which exhibit improved quality and piezoelectric response, which are formed in a DC magnetron reactive sputtering system. The dielectric material is deposited onto a substrate, and the deposition is interrupted before a highly insulating film is grown on the chamber interior. Then, the reactive gas is removed from the chamber and replaced with an inert gas, and a layer of metal is deposited on the chamber interior. This deposition of a metal layer conceals the highly insulating film on the chamber interior thereby improving the quality and piezoelectric response of the dielectric thin films. During the step of depositing a metal layer, the deposited substrate is shielded in order to prevent metal from being deposited on the substrate. Then, the deposition of dielectric material on the substrate and deposition of the metal layer on the chamber interior is repeatedly alternated until a desired thickness of the dielectric thin film has been reached.
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Aluminum Nitride Contour Mode Resonators

Aluminum Nitride Contour Mode Resonators

During experiment 1 for determining the best deposition conditions, the aluminum target was poi- soned. Poisoning is a result of a build up of product on the surface of the sputtering target resulting in a gradual increase in overall chamber or plasma impedance and if severe enough, it will lead to the inability to spark the chamber plasma [63, 64]. From Table 6.1 and Figure 6.7 there is no AlN peaks of any orientation for runs A through H. Table 6.1 show a series of depositions from A through H, where A-HF through F-HF represent an HF dip, which was used to remove any native oxide on the silicon substrate used for deposition, as this was thought to have some impact on the final AlN orientation. All future depositions have the 30 second HF dip. In experiment 1 the deposition duration, platen rotation, ratio of argon to nitrogen flow rate and chamber pressure were each changed to observe the effect on aluminum nitride deposition.
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Deposition of c-axis orientation aluminum nitride films on flexible polymer substrates by reactive direct-current magnetron sputtering

Deposition of c-axis orientation aluminum nitride films on flexible polymer substrates by reactive direct-current magnetron sputtering

incident particle kinetic energy which enhances the mobility of the atoms deposited and the migration distance, thus beneficial for the growth of (002) oriented crystallites [24]. However, once the sputtering power exceeded 500 W, the intensity of the AlN (002) peak is reduced and the FWHM increases to 0.376°. This may be caused by the deterioration of the substrate at high temperatures at high power deposition as evidenced by the peeling off of the samples deposited at powers higher than 500W, and/or insufficient atom migration at such a high deposition rate and the high energy incident atoms. At high deposition rate, atoms do not have sufficient time to rearrange on the surface before the next atoms are deposited, leading to a deteriorated crystal structure. Furthermore, the incident atoms have very high energy, which can damage the surface of the newly formed AlN layer, thus destroying the (002) crystal orientation.
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Doping Reaction of some Nanotubes with Aluminium Atom: A Thermodynamic PM6 and ONIOM Investigation

Doping Reaction of some Nanotubes with Aluminium Atom: A Thermodynamic PM6 and ONIOM Investigation

We constructed the (8,0) zigzag and the (4,4) armchair CNT and BNNTs and optimized them using semiempirical quantum chemical method PM6 method and ONIOM method. Then we doped them with one atom of aluminium for more calculations All nanotube lengths were about 1-nm, open-ended and defect free. The two caps of all nanotubes were saturated with hydrogen atoms to simulate the effect of a longer nantube and to prevent the nanotube

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Aluminum nitride films by reactive sputtering

Aluminum nitride films by reactive sputtering

N2 Composition Figure 3-3 Affect of annealing on thickness 51 Figure 3-4 Affect of annealing on refractive index 52 Figure 3-5 Capacitance as a function of plate area 52 Figure 3-6 Optic[r]

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Feasibility of Plasma Nitriding for Effective Surface Treatment of Pure Aluminum

Feasibility of Plasma Nitriding for Effective Surface Treatment of Pure Aluminum

Cast aluminum with 99.99% purity was successfully plasma nitrided using nitrogen and hydrogen mixed gas. Pre-sputtering was carried out prior to plasma nitriding in order to eliminate surface oxide film. Sputtering and nitriding durations were varied from 3.6 to 18 ks and 72 ks to 252 ks, respectively. The samples were nitrided at 823 and 873 K to observe the effect of nitriding temperature. The nitrided samples were analyzed by GIXD, XPS, and TEM. Through GIXD and XPS results, formation of AlN was distinctly detected as a nitrided surface. Cross- sectional microstructure of nitrided samples showed that AlN was formed with the thickness up to 3–5 mm. AlN formation is controlled by the diffusion process. The thickness of AlN layer was determined by the nitriding time and temperature. Partial degradation of AlN in the vicinity of the free surface occurred due to its reaction with moisture in air. Partial detachment of AlN layer occurred due to the residual thermal stress, which was caused by the difference in thermal expansion coefficient between AlN and substrate of Al.
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Al-rich AlGaN and AlN Growth on Bulk AlN Single Crystal Substrates

Al-rich AlGaN and AlN Growth on Bulk AlN Single Crystal Substrates

which resulted in a smooth surface morphology even with high BSF densities. The BSF density could only be reduced through the lateral growth of the wing region over the LEO mask. However, under growth conditions that promoted the slate-like morphology, the only way to reduce the density of stripes was to reduce the density of BSFs in the wing regions of the LEO, therefore making it seem necessary for the BSF to be present for the characteristic stripe along the ±[0001] to form. The conclusion was that if a slate-like morphology is present then SFs should be as well. These claims are slightly contrary to the results shown in Figure 3-20, which indicates that the slate-like morphology, present in the lower growth temperature layer, is not necessarily related to BSFs. It could be that BSFs simply promote the formation of the (000- 1) facets and that through appropriate growth conditions, similar surface features can become energetically favorable. All of the results presented in this section indicate that further investigations are needed to establish a better understanding of the surface kinetics and energetics involved in the formation of the slate-like morphology seen in non-polar III-nitrides from literature and here in the (1-100) homoepitaxial AlN films grown at the lower growth temperatures, since such strong claims have been made to correlate this morphology to BSFs in the literature.
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STRUCTURE AND MECHANICAL AND TRIBOLOGICAL PROPERTIES OF MAGNETRON SPUTTER DEPOSITION OF STAINLES-STEEL NITRIDE AND CARBIDE THIN FILMS WITH TRANSITION METAL ADDITIVES, Faisal Alresheedi

STRUCTURE AND MECHANICAL AND TRIBOLOGICAL PROPERTIES OF MAGNETRON SPUTTER DEPOSITION OF STAINLES-STEEL NITRIDE AND CARBIDE THIN FILMS WITH TRANSITION METAL ADDITIVES, Faisal Alresheedi

Residual stresses are generally produced close to surface interfaces when modifying a sample’s mechanical properties. The effects of residual stresses in S-phase layers have been discussed frequently. One particular experiment, performed by T. Christiansen and M. Somers [55], used x-ray analysis data to recreate residual stress profiles in 316L stainless targets applying a low processing temperature. They reported that large values of residual stress of about - 7.5GPa could be obtained for treated austenitic steel samples. These values were found when examining the sample with the (200) expanded austenite reflection. In addition, Grigull and Parascandola [31] found that increasing the nitrogen content in the nitride layer leads to an increase in the residual stress and a compressive stress of 2.5-3 GPa was obtained when the S- phase contained 23% N 2 .
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An Etching Study for Self-Aligned Double Patterning

An Etching Study for Self-Aligned Double Patterning

Carbon has been used in industry as a hardmask for a while, especially at the beginning of the start of double patterning. The first hardmasks were using a diamond-like amorphous carbon, chosen due to its high selectivity to any number of standard CMOS materials. [27, 29, 59–61] To call the material used diamond-like is a bit of a misnomer as the material that was generated via a CVD process generally resided within the ta- C:H and a-C:H regions of the ternary phase diagram as depicted by Figure 2.27. As features got smaller the a-carbon materials became too thick and changes needed to be made [62], so carbon based spin-on materials were developed. Initially there were some troubles producing a comparable material to the a-carbon [63, 64], namely with concerns to wiggling [65, 66]. These problems started to go away when the fullerene material
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Characterization of InGaN and InAlN epilayers by microdiffraction X-Ray reciprocal space mapping

Characterization of InGaN and InAlN epilayers by microdiffraction X-Ray reciprocal space mapping

divergences of ~0.8 mrad. The demagnification factor of the lens system was estimated to be ~58. The required sample rotations and translations were performed using a high precision 5- circle Huber diffractometer with 0.1 millidegree resolution and a Huber XYZ sample stage. A Pilatus 100k detector with pixel size of 0.172×0.172 mm was used to record the diffracted X-rays from the sample. The measurements of the full 3D shape of the ( 10 1 3 ) Reciprocal Lattice Point (RLP) were done in skew symmetric geometry by changing the incident angle ω to the

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Fe Pd Ferromagnetic Shape Memory Alloy Thin Films Made By Dual Source DC Magnetron Sputtering*

Fe Pd Ferromagnetic Shape Memory Alloy Thin Films Made By Dual Source DC Magnetron Sputtering*

The morphology and size ofgrains were investigated for all annealed films with various Pd contents and thickness and the results ofAFM images are shown in Fig. 6. As seen, the grain size ofannealed films becomes larger with increasing thickness and the grains appear to be somewhat smaller for films with higher Pd content. The grain morphology is essentially the same regardless Pd content and crystal structures, especially, when their grains are small. In this case, grains do not show any substructure. When grains are larger, on the other hand, plate-form markings appear. No detailed observations have been pursued in the present study to identify what these markings are. However, they are considered to be martensite plates with different crystal structures. Further detailed observations are underway using, for example, the electron back reflection channeling method to identify grain orientations and habits planes of the plate- form markings.
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Sputter growth and characterization of metamagnetic B2-ordered FeRh epilayers.

Sputter growth and characterization of metamagnetic B2-ordered FeRh epilayers.

done using any temperature dependent magnetometer with sufficient sensitivity, for instance using the magneto-optical Kerr effect or a vibrating sample magnetometer. In Figure 4 we show the temperature dependence of the magnetization M, measured using a superconducting quantum interference device (SQUID) magnetometer. Measurements were made in the temperature range of 275-400 K with a temperature sweep rate of 2 K/min. The curve shown displays the anticipated AF → FM transition (heating) and FM → AF transition (cooling) with a 15 K thermal hysteresis. This measurement was made at high field (50 kOe) and yielded a transition temperature T T ≈ 365 K. The transition temperature is
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FabricateUltra Thin Alumina Membranes
masks to Produce Al-Nanostructure by Using
Physical Vapor Deposition Technique

FabricateUltra Thin Alumina Membranes masks to Produce Al-Nanostructure by Using Physical Vapor Deposition Technique

There are three widely-used templates that are prepared using self-assembly process: ultra-thinaluminamembrance (UTAM), monolay polystyrene (PS), sphere arrays, and block copolymer (BCP) patterns. The surface patterns synthesized using these templates have promising device application potentials due to the low-cost and time-saving fabrication processes of surface structures. Asthree major pattering templates derived from self-assembly processes ,PS,BCP and UTAM templates have their own unique aspects. First, the features size of the building blocks of the surface patterns prepared using BCP; UTAM and PS templates can be adjusted within the range of about 5-50nm, 5- 500 nm and 50nm-4.5µm respectively. This means that these three template- based surface pattering techniques can cover the whole range from the quantum size range. UTAM is a hard template of metallic oxide that can only be removed by chemical dissolution. Moreover the UTAM has parallel-aligned cylindrical Nano prose [5, 6].
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Preparation And Mechanical Behaviour Of Al-6063-Sicp Aluminum Matrix Composites By Using Stir Casting Technique

Preparation And Mechanical Behaviour Of Al-6063-Sicp Aluminum Matrix Composites By Using Stir Casting Technique

The elastic limit of any material is the point at which it can no longer return to its original shape or size. The elastic limit determined by a torsion test is equal to the slope of the line from the start of testing to the proportional limit. This relationship was first measured by Sir Robert Hooke in 1678. Hooke's Law states that stress is directly proportional to strain until the proportional limit is reached, at which point the object tested will begin to show signs of stress. After testing, metal materials are categorized as being either ductile or brittle. Ductile metals such as steel or aluminum have high elastic limits and can withstand a great deal of strain before breaking. Brittle materials such as cast iron and concrete have
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Design and Analysis of MEMS Based Aluminum Nitride (AlN), Lithium Niobate (LiNbO3) and Zinc Oxide (ZnO) Cantilever with Different Substrate Materials for Piezoelectric  Vibration Energy Harvesters Using  COMSOL Multiphysics Software

Design and Analysis of MEMS Based Aluminum Nitride (AlN), Lithium Niobate (LiNbO3) and Zinc Oxide (ZnO) Cantilever with Different Substrate Materials for Piezoelectric Vibration Energy Harvesters Using COMSOL Multiphysics Software

DOI: 10.4236/ojapps.2019.94016 189 Open Journal of Applied Sciences singular polar axis causing the formation of anelectric dipole in the unit cell due to the lack of coincidence of the centre of mass of the negative charge in the N tetrahedrons and the positive charge of the Al atom. The dipolegives rise to a spontaneous polarization. Moreover, in the presence of strain, apiezoelectric po- larization is created at the AlN/Al interface due to the lattice mismatch between AlN and the Al substrates that can create fields in the MV/cm range. However, the lattice mismatch in ZnO/Al cantilevers is much larger than lattice mismatch in AlN/Al cantilevers.
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Thermal Conductivity of Epoxy Compounds Enriched With Aluminium Nitride (Aln)

Thermal Conductivity of Epoxy Compounds Enriched With Aluminium Nitride (Aln)

Here an ANSYS analysis is shown evaluating the temperature distribution of aluminium nitride filled epoxy composite in static thermal model. By taking different arrangemts of fillers in terms of volume fraction and assuming certain temperature along the side of the matric cube meshing is done. The heat flow is assumed to be uniform along the selected faces. Final model of temperature distribution is shown below.

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New applications of excimer lamps to the low temperature photo-deposition of thin films

New applications of excimer lamps to the low temperature photo-deposition of thin films

This thesis is divided into 5 parts. In chapter 1, the photo-chemical vapour deposition is presented, as a technique allowing films to be deposited at low temperatures for semiconductor applications. The description of the photo-CVD reactor developed at UCL is given, together with a short review on the characterisation techniques used. The importance of well understanding the theory of excimers as the main precursor in this technique leads to chapter 2. In particular, the wide range of radiations that can be emitted with such lamps is presented. Various devices are described, enabling the generation of excimer continua from 308nm (xenon chloride), down to 126nm (pur argon). The possibilities offered by the excimer lamps available at UCL are reviewed, in terms of geometry and power output, and a few techniques allowing the measurement of VUV radiations are presented. Chapter 3 concentrates on two direct applications of the ultraviolet radiation. In fact, since a new type of vacuum ultraviolet source became available during this project, new areas of application were investigated, namely the direct VUV enhanced generation of ozone, as well as various other applications of the UV enhanced organometallic technique (MOD). In fact, at the time of writing this thesis, a new project is about to begin at UCL to further extend those MOD experiments.
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Fabrication of AlN Coatings by Reactive Atmospheric Plasma Spray Nitriding of Al Powders

Fabrication of AlN Coatings by Reactive Atmospheric Plasma Spray Nitriding of Al Powders

particles temperature with increasing spray distance which lead to reducing the deposition efficiency of the particles. Also, with increasing spray distance some sprayed particles deviated from substrate. Moreover, complete nitriding of some Al particles (and formation of AlN particles) during flight with increasing spray distance prevents its deposition the formed AlN particles during plasma cannot deposit because it doesn’t have a molten phase which is required for deposition in thermal spray process. Therefore, though it was possible to fabricate thick c-AlN/Al composite coating by APS and with increasing the spray distance the nitride content was enhanced, the coating thickness was suppressed. In other words it was difficult to obtain thick AlN based coatings under these conditions. In order to fabricate thick AlN coatings in APS process further information about the nitriding phenomena of Al particles is required. Therefore, the nitriding reaction of Al particles was investigated during flight and after deposition on the substrate in the following sections.
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Development of corrosion resistant niobium based PVD coatings

Development of corrosion resistant niobium based PVD coatings

Potentiodynamic polarisation scans of untreated stainless steel and of one coated sample (Ubias=-800V, P=8.3*10'3mbar) are shown in fig.2. The untreated stainless steel passivates between -200m V and +200mV due to the formation of a Cr rich oxide layer. However, the stability o f this protective layer is restricted by the presence of chloride anions which leads to breakdown of the passive film i.e. pitting at +200mV followed by severe localised anodic dissolution of the steel which is indicated by the steep increase in current density. The introduction of Nb leads to much improved corrosion behaviour as can be seen from fig.2. The pitting potential is raised to approximately lOOOmV compared to 200mV for untreated stainless steel. Accordingly, the anodic current density is reduced to < 10‘5Acm‘2 opposed to the maximum recordable current density of KT1 Acm'2 for stainless steel. Further results on the corrosion resistance are summarised in fig.3. Fig.3a,b outline the influence of the Ar background pressure during the metal ion etch prior to deposition as a function of the bias voltage during the etching step. Fig.3c shows the results of the etched-only substrates with no additional Nb coating. In all three cases the pitting potentials (Eph) and the anodic current densities (taken at +700mV) are plotted against the bias voltage. Suprisingly, all three conditions show a very similar behaviour. Neither the Ar background pressure nor the presence of a 300nm Nb sputter top coating show a distinct influence on the corrosion resistance. In all three cases the highest corrosion resistance is achieved with “medium” bias voltages that is -600V and - 800V (i.e. ion energies of 1.8keV and 2.4keV), while it is reduced when using bias voltages of the low and the high end of the employed scale.
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Influence of Sputter Deposition Time on the Growth of c Axis Oriented AlN/Si Thin Films for Microelectronic Application

Influence of Sputter Deposition Time on the Growth of c Axis Oriented AlN/Si Thin Films for Microelectronic Application

oms with more energy favor the formation of {002} sur- face plane. Another factor, which strongly influences the formation of preferred surface planes, is packing habit of such planes. For the development of close-packed sur- face planes the ad atoms need a longer time to accom- modate themselves into the low energy configured lattice sites before the arrival of the next layer of reactive spe- cies. A low deposition rate is necessary in such cases [13]. Hence, we predict that at a deposition time of 8 min, the coated film has low deposition rate, which favors the formation of highly oriented (002) preferential plane with enhanced crystal quality, which can provide good piezo- electric response.
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