Direct Alpha Ta Formation on TaN by Resputtering for Low Resistive Diffusion Barriers

2008 ◽  
Vol 8 (5) ◽  
pp. 2582-2587 ◽  
Author(s):  
Jung-Chih Tsao ◽  
Chuan-Pu Liu ◽  
Ying-Lang Wang ◽  
Kei-Wei Chen
Keyword(s):  
Surface Treatment ◽  
Resistivity Measurement ◽  
Beta Phase ◽  
Alpha Phase ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Body Center Cubic ◽  
Argon Ion Bombardment ◽  
Body Center ◽  
Two Phases

The Ta/TaN bilayer exhibits the best performance in the Cu metal multilevel interconnects, because it provides good coherence between Cu and dielectric layer. In the Ta/TaN bilayer, Ta has two phases: alpha-phase of body center cubic is preferred due to its lower resistivity (15–60 μΩ-cm), whereas beta-phase of tetragonal should be avoided due to high resistive (∼150–250 μΩ-cm). However, beta Ta most commonly forms on fcc TaN. Here we provide a simple scheme to bypass this high resistive phase by resputtering TaN prior to Ta deposition. We found that, with surface treatment by argon ion bombardment for enough time, alpha Ta phase can be directly formed, which is supported both by X-ray diffraction and resistivity measurement. Depth profiles of all elements from Auger electron spectroscopy reveals that the surface treatment induces a nitrogen deficient surface layer due to different sputtering yield, which causes phase changes from fcc TaN to hcp Ta2N followed by bcc Ta(N) and provide a favorable lattice constant for Ta alpha-phase formation.

Sputter-Deposited Bcc Tantalum on Steel with the Interfacial Tantalum Nitride Layer

2001 ◽  
Vol 697 ◽  
Author(s):  
Anamika Patel ◽  
Leszek Gladczuk ◽  
Charanjeet Singh Paur ◽  
Marek Sosnowski
Keyword(s):  
Corrosive Wear ◽  
Beta Phase ◽  
Nitride Layer ◽  
Alpha Phase ◽  
Tantalum Nitride ◽  
Nuclear Reaction Analysis ◽  
Sputtered Films ◽  
Bcc Structure ◽  
Two Phases ◽  
Sputter Deposited

AbstractTantalum has mainly two phases: alpha phase (bcc structure) and beta phase (tetragonal structure). The meta-stable beta phase is usually obtained in sputtered films. Alpha phase is preferred over the beta for some applications as beta phase is very brittle. One of such application is to protect steel from the erosive and the corrosive wear. It was found that with the intermediate layer of tantalum nitride the preferred alpha phase was grown on steel by DC magnetron sputtering technique. Electrical and structural properties of these films were studied by four-point probe measurement and x-ray diffraction (XRD). Stoichiometry of the interfacial tantalum nitride layer was investigated by nuclear reaction analysis (NRA). Influence of the interfacial film thickness and the ratio of argon and nitrogen gas during reactive deposition of tantalum nitride on the tantalum phase were investigated. This work also reports on the dependence of tantalum phase on the substrate temperature (100-400°C) during sputtering in Ar and Kr gases.

scholarly journals Structural characterization of liquid phase sintered silicon carbide by high-resolution X-ray diffractometry

Cerâmica ◽  
2005 ◽  
Vol 51 (318) ◽  
pp. 168-172 ◽  
Author(s):  
C. A. Kelly ◽  
P. A. Suzuki ◽  
S. Ribeiro ◽  
S. Kycia
Keyword(s):  
Silicon Carbide ◽  
High Resolution ◽  
Mixed Oxide ◽  
Beta Phase ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
Solid Solution Formation ◽  
X Ray ◽  
Synchrotron Light

Silicon carbide (SiC) was sintered using two different additives: AlN-Y2O3 or AlN-CRE2O3. CRE2O3 is a mixed oxide formed by Y2O3 and rare-earth oxides. The crystalline structures of the phases were analyzed by high-resolution X-ray diffraction using synchrotron light source. The results of the Rietveld refinement of the mixed oxide show a solid solution formation. In both silicon carbide samples prepared using AlN-Y2O3 or AlN-CRE2O3 3C (beta-phase) and 6H (alpha-phase) polytypes were found. The structural and microstructural results for both samples were similar. This is an indication of the viability of the use of CRE2O3 in substitution for Y2O3 as additive to obtain dense materials.

Stress and Phase Changes in Ion-Assisted Evaporation of Thin Tantalum Films

1991 ◽  
Vol 235 ◽  
Author(s):  
R. A. Roy ◽  
Philip Catania
Keyword(s):  
Alpha Phase ◽  
Ion Flux ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Tantalum Films ◽  
Ion Energies ◽  
Argon Ion ◽  
Flux Incident

ABSTRACTIon-assisted evaporation was used to study the stress and phase changes in thin Ta films. Using a series of ion energies from 63 to 500 eV, the stress in 100 nm thick films was changed from tensile to compressive by increasing the argon ion flux incident on the growing films. The resulting films were characterized primarily by x-ray diffraction and electrical resistivity measurements, as well as RBS. The resistivity in all sets of films shows a large decrease with increasing argon ion flux. The x-ray diffraction results are somewhat more complex, but suggest that increasing ion flux does change the amount of alpha phase present.

Influence of Fe Content of Ti-Mn-Fe Alloys on Phase Constitution and Heat Treatment Behavior

2012 ◽  
Vol 706-709 ◽  
pp. 1893-1898 ◽  
Author(s):  
Masahiko Ikeda ◽  
Masato Ueda ◽  
Takahiro Kinoshita ◽  
Michiharu Ogawa ◽  
Mitsuo Niinomi
Keyword(s):  
Vickers Hardness ◽  
Beta Phase ◽  
Optical Microscope ◽  
Alpha Phase ◽  
Omega Phase ◽  
X Ray Diffraction ◽  
Fe Content ◽  
Valence Electrons ◽  
Fe Alloys ◽  
Stabilizing Element

If Mn could be partly substituted by Fe, Ti-Mn-Fe alloys would be less costly than Ti-Mn alloys. Furthermore, the use of iron as a beta-stabilizing element is more suitable than the use of manganese from a situation of an element strategy. In this study, 4.26 was admitted as the average ratio of valence electrons to atoms, e/a. The compositions of Mn and Fe were chosen under 4.26 as e/a. We investigated the influence Fe in selected Ti-Mn-Fe alloys by performing electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In solution-treated and water-quenched 10Mn alloy, the beta and athermal omega phases were identified, while only the beta phase was identified in 8.7Mn-1Fe, 6.1Mn-3Fe, and 3.5Mn-5Fe alloys. In all alloys, equiaxial beta grains were observed by optical microscope. The resistivities at room and liquid-nitrogen temperatures and the Vickers hardness were relatively invariant across all Ti-Mn-Fe alloys, except for the Vickers hardness of the 5Fe alloy. During aging at 773 K, an isothermal omega phase precipitated in only the 3.5Mn-5Fe alloy, whereas only the alpha phase precipitated in the others.

scholarly journals Nanofabrication of Iron-Cobalt (FeCo) Alloy by Sol-gel Method

2021 ◽  
Vol 1 (1) ◽  
pp. 111-114
Author(s):  
Majid Farahmandjou ◽  
Parastoo Khalili
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Sem Analysis ◽  
The Body ◽  
X Ray Diffraction ◽  
Body Center Cubic ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Bcc Structure ◽  
Body Center

Background and Introduction: Metal oxides (MOs) have been extensively used in a large range of engineering and medical applications. Methods: FeCo nanoparticles (NPs) were successfully synthesized by the solgel method in the presence of a powerful reducing agent-sodium borohydride (NaBH4). The structure, morphology, and optical properties of NPs were analyzed by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) at room temperature. Results: The XRD spectrum showed the body center cubic (BCC) structure of the samples after heat treatment at 500 °C. The SEM analysis exhibited that the particle size of as-synthesized and annealed samples was approximately 40 nm and 22 nm, respectively. Conclusion: The TEM investigations showed the rod-shaped sample of annealed NPs. The optical studies of the FTIR analysis revealed the starching bound of Fe-Co at the frequencies of 673 cm-1, 598 cm-1, and 478 cm-1.

Quantitative X-Ray Microanalysis of Ti Alloys

1980 ◽  
Vol 38 ◽  
pp. 142-143
Author(s):  
C. G. Rhodes
Keyword(s):  
Mechanical Properties ◽  
Thin Foil ◽  
Beta Phase ◽  
Alpha Phase ◽  
Foil Thickness ◽  
X Ray ◽  
Volume Fractions ◽  
Β Phase ◽  
Two Phases ◽  
Two Parameters

This paper discusses the results of a systematic study of the effect of subtransus (below the β/α+β phase boundary) heat treatments on microstructure and mechanical properties in two α+β titanium alloys. Quantitative X-ray microanalysis was used to measure the compositions of the alpha and beta phases in order to evaluate their influence on mechanical properties. Ti-6A1-4V and Ti-4.5A1-5Mo-l.5Cr were treated to produce a microstructure consisting of equiaxed primary alpha-phase grains separated by a continuous beta phase matrix. The two parameters evaluated in this work were (1) volume fractions and (2) compositions of the alpha and beta phases. Measurement of volume fractions was straightforward; however, the measurement of the compositions of the two phases required development of a reliable comparative quantitative X-ray microanalytic technique for thin foil analysis using a conventional transmission electron microscope with STEM capability. Although our X-ray energy dispersive system included a typical thin foil computer program, it was not used because of the error introduced by estimating factors such as foil thickness and phase density.

Preparations Effects on Amorphous/Nanocrystal Ni-Mo Alloys Structure and Properties

2011 ◽  
Vol 217-218 ◽  
pp. 21-26
Author(s):  
Ning Li ◽  
Cheng Hui Gao ◽  
Guang Ming Cheng
Keyword(s):  
Chemical Properties ◽  
Xrd Analysis ◽  
Dimensional Structure ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Forming Mechanism ◽  
Body Center Cubic ◽  
The Face ◽  
Body Center ◽  
Binary Compounds

Ni-Mo alloys have been studied as a prospected cathode for its higher hydrogen evolution reaction properties than other binary compounds. The eletrodeposition parameters and its effects have been investigated in forming Ni-Mo alloys in the present study by measuring the structure and properties of deposits. The forming mechanism of Ni-Mo amorphous deposit is discussed from point of the elements component of view. The X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) microstructures show that the molybdenum content in the deposit is increased with the molybdate concentration increase, and the deposit structure can be parted several stages- nanocrystal, nanocrystal/amorphous, amorphous, crystalline, or the mixed configuration due to the variation of Mo atom content. The forming mechanism of the deposit of Ni-Mo alloys is attributable to the repulsive aggradations as of the molybdenum chemical properties and electronic shell structure. When the atom rate of Ni/Mo is higher than 0.35, the deposit is the face center cubic (fcc) configuration, while lower than 0.35, the deposit is the monoclinic hexagon crystalloid configuration or body center cubic (bcc) dimensional structure.

Synthesis of New Nitrides Using Solid State Oxide Precursors

1993 ◽  
Vol 327 ◽  
Author(s):  
Joel D. Houmes ◽  
David S. Bem ◽  
Hans-Conrad Zur Loye
Keyword(s):  
Solid State ◽  
Magnetic Measurements ◽  
Reaction Times ◽  
Magnetic Ordering ◽  
Beta Phase ◽  
Alpha Phase ◽  
Transition Metal Nitrides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Prismatic Coordination

AbstractSeveral novel transition metal nitrides were synthesized via ammonolysis of solid state oxide precursors at temperatures ranging from 700°C-900°C and reaction times ranging from 12 hours to 4 days. Both intermetallic nitrides, Fe3Mo3N and Co3Mo3N, and ionic/covalent nitrides, FeWN2, MnWN2, Ta5N6 and Nb5N6, were prepared by this method. The products were characterized by powder X-ray diffraction and their structures were determined by powder X-ray Rietveld refinement. The intermetallic nitrides were found to be isostructural with the eta-carbide structure, Fe3W3C, while the ionic/covalent nitrides have layered structures, with metals in octahedral and trigonal prismatic coordination environments. Two polymorphs of the MnWN2 composition, α-MnWN2 and β-MnWN2, were isolated after ammonolysis at 700°C and 800°C, respectively. While the alpha phase can be converted into the beta phase by heating to 800°C under ammonia, annealing the beta phase at 700°C did not result in a structural transformation. Magnetic measurements show that FeWN2 orders antiferromagnetically at 45K. The magnetic ordering temperature was confirmed by M6ssbauer spectroscopy. All the other nitrides were paramagnetic down to 5K. Conductivity measurements show that FeWN2 and MnWN2 are metallic.

The Characterization Of Organic Charge Transfer Superconductors By Microreflectance Spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 272-273
Author(s):  
S. L. Hill ◽  
K. Krishnan ◽  
J. R. Ferraro
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Beta Phase ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
A Value ◽  
Charge Transfer Salts

Certain classes of organic charge-transfer salts demonstrate superconducting behavior at liquid helium temperatures. Single crystal x-ray diffraction and infrared microreflectance analysis have been performed on several conducting systems to associate the nature of the crystalline structure with the electrical conductivity. The infrared spectrum for a single crystal salt exhibits absorptions which correlate with superconducting behavior.Discussion Williams and coworkers have performed x-ray Crystallography experiments to demonstrate the presence of an anion cavity between radical cation stacks- of bis(ethylenedithio)- tetrathiafulvalene (ET). The sulfur…sulfur interstack distance in a beta or kappa phase salt assumes a value less than the Vanderwaals distance and exhibit a superconducting (two dimensional) metal behavior (verified by Fermi surface calculations) at 1-20K. The structures of alpha and beta phase ET2I3 suggest the potential for several potential intermolecular interaction modes. It may be observed that the beta phase permits both interstack as well as H … X anionic interactions, whereas these interactions are less likely to occur in the alpha phase.

Preparation and Characterization of High Purity β-SiC Powder

2012 ◽  
Vol 512-515 ◽  
pp. 3-6 ◽  
Author(s):  
Eun Jin Jung ◽  
Yoon Joo Lee ◽  
Soo Ryong Kim ◽  
Woo Teck Kwon ◽  
Se Young Choi ◽  
...  
Keyword(s):  
Reaction Time ◽  
Beta Phase ◽  
Alpha Phase ◽  
Carbon Powder ◽  
X Ray Diffraction ◽  
Synthetic Temperature ◽  
Diffraction Peaks ◽  
Lower Temperature ◽  
Metallic Impurities

SiC powder can be produced generally through the Acheson process and it is required long carbothermic reaction time of SiO2 with carbon powder around 2200 °C ~ 2400 °C. Due to the high reaction temperature and long reaction time of the process, the powders produced have a large particle size and consist of mostly alpha phase SiC. Synthetic temperature of beta phase SiC powder is known to produce at 1700 °C ~ 1900 °C which is lower temperature than that of alpha phase SiC powder. We prepared β-SiC powder by heating precursor derived from the mixture of phenolic resin and tetraethyl orthosilicate. The precursor was heated at 1800 °C for 4 h in an Ar atmosphere. In order to examine the pyrolysis residue after the heat treatment, the SiC powder was analyzed with XRD and SEM. The X-ray diffraction result of the SiC powder shows the diffraction peaks around 35°, 60°, and 73° corresponded to the beta SiC phase. β-SiC powder prepared in this study contains lower metallic impurities compare than that of α-SiC powder prepared from Acheson method and is able to use as a good starting material for SiC single crystal growing.

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