Classification of the Modes of Dissociation in Immiscible Cu-Alloy Thin Films

1999 ◽  
Vol 564 ◽  
Author(s):  
K. Barmak ◽  
G. A. Lucadamo ◽  
C. Cabral ◽  
C. Lavoie ◽  
J. M. E. Harper
Keyword(s):  
Thin Films ◽  
Driving Forces ◽  
Texture Evolution ◽  
Substantial Reduction ◽  
Alloying Elements ◽  
X Ray Diffraction ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Evolution Of Microstructure

AbstractWe have found the dissociation behavior of immiscible Cu-alloy thin films to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. The motivation for these studies was to use the energy released by the dissociation of an immiscible alloy, in addition to other driving forces commonly found in thin films and lines, to promote grain growth and texture evolution. In this work, the dissociation behavior of eight dilute (3.3 ± 0.5 at% solute) binary Cu-systems was investigated, with five alloying elements selected from group VB and VIB, two from group VillA, and one from group 1B. These alloying elements are respectively V, Nb, Ta, Cr, Mo, Fe, Ru and Ag. Several experimental techniques, including in situ resistance and stress measurements as well as in situ synchrotron x-ray diffraction, were used to follow the progress of solute precipitation in approximately 500 nm thick films. In addition, transmission electron microscopy was used to investigate the evolution of microstructure of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure and texture often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900°C. However, in most cases, substantial reduction in resistivity of the films took place at temperatures of interest to metallization schemes, namely below 400°C.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

In situ x-ray diffraction of solution-derived ferroelectric thin films for quantitative phase and texture evolution measurement

2012 ◽  
Vol 112 (10) ◽  
pp. 104109 ◽  
Author(s):  
Krishna Nittala ◽  
Sungwook Mhin ◽  
Jacob L. Jones ◽  
Douglas S. Robinson ◽  
Jon F. Ihlefeld ◽  
...  
Keyword(s):  
Thin Films ◽  
Texture Evolution ◽  
Ferroelectric Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Phase

Growth of Cubic SiC Thin Films on Silicon from Single Source Precursors by Supersonic Jet Epitaxy

1996 ◽  
Vol 441 ◽  
Author(s):  
Jin-Hyo Boo ◽  
Scott A. Ustin ◽  
Wilson Ho ◽  
H. Paul Maruska ◽  
Peter E. Norris ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Supersonic Jet ◽  
Silicon On Insulator ◽  
X Ray Diffraction ◽  
Molecular Precursors ◽  
Transmission Electron ◽  
Supersonic Jet Epitaxy ◽  
Soi Substrates

AbstractCubic SiC thin films have been grown by supersonic jet epitaxy of single molecular precursors on Si(100), Si(111) and Separation by IMplanted OXygen (SIMOX) silicon on insulator (SOI) substrates at temperatures in the range 780 - 1000 °C. Real-time, in situ optical reflectivity was used to monitor the film growth. Films were characterized by ellipsometry, x-ray diffraction (XRD), and transmission electron microscopy (TEM). Monocrystalline, crack-free epitaxial cubic SiC thin films were successfully grown at 830 °C on carbonized Si(111) substrates using supersonic molecular jets of dimethylisopropylsilane, (CH3)2CHSiH(CH3)2, and diethylmethylsilane, (CH3CH2)2SiHCH3. Highly oriented cubic SiC thin films in the [100] direction were obtained on SIMOX(100) at 900 °C with dimethylisopropylsilane and on Si(100) at 1000 °C with diethylmethylsilane. A carbonized Si(100) surface was found to enhance SiC deposition from diethylmethylsilane at a growth temperature of 950 °C.

Synchrotron Characterization of Texture and Stress Evolution in Ag Films

2007 ◽  
Vol 1027 ◽  
Author(s):  
Aaron Vodnick ◽  
Michael Lawrence ◽  
Bethany Little ◽  
Derek Worden ◽  
Shefford Baker
Keyword(s):  
Real Time ◽  
Driving Forces ◽  
Texture Evolution ◽  
High Energy ◽  
Fiber Texture ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
The Individual

AbstractReal-time in-situ synchrotron x-ray diffraction measurements were performed at the Cornell High Energy Synchrotron Source to characterize both the texture evolution and stresses within the individual texture components of Ag films during recrystallization. As deposited films had a nearly perfect (111) fiber texture. During isothermal anneals, stress and texture were characterized in real-time as the texture evolved into a strong (001) fiber. An Avrami analysis of the evolving texture fractions yielded very different activation energies for films on different barrier layers, suggesting different governing mechanisms were responsible for secondary grain growth. The strains were used to test a common model for texture prediction that assumes the same strain within each texture component. It was found that secondary (001) grains were able to grow primarily strain free. Selection for this strain energy minimizing orientation occurred during the nucleation process during which texture interactions play an important role. By using these real time measurements, we are able to show that driving forces for texture transformations in metal films may not be as simple previously described.

Microstructures of Cu- and Y-rich YBa2Cu3O7−x thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 38-39
Author(s):  
A.F. Marshall
Keyword(s):  
Thin Films ◽  
Critical Currents ◽  
Electron Beam Evaporation ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Defect Microstructure

The defect microstructure of Cu- and Y-rich thin films of the high Tc superconductor YBa2Cu3O7−x (123) is of interest for several reasons. The highest Tc' reported for well-ordered stoichiometric films are typically 90-91 K. Post-annealed Cu- and Y-rich films may exhibit Tc's of 95-96 K. X-ray diffraction showed these non-stoichiometric films to be a highly faulted mixture of the 123 and 248 (Y2Ba4Cu8O16,Tc=80 K) phases. In situ films made by sputtering or electron beam evaporation typically show sharp but depressed Tc's (75-85 K); for our films these values approach 90 K when the films are Cu- and Y-rich. Both post annealed and in situ films exhibit high critical currents on and off stoichiometry; the pinning characteristics, which may be highly influenced by the defect microstructure, are superior for the in situ techniques.Transmission electron microscopy analysis shows that excess Cu and Y can be incorporated both as stacking fault (SF) defects and as second phase precipitates.

Grain growth in nanocrystalline copper thin films investigated by non-ambient X-ray diffraction measurements

2009 ◽  
Vol 24 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Y. Kuru ◽  
M. Wohlschlögel ◽  
U. Welzel ◽  
E.J. Mittemeijer
Keyword(s):  
Thin Films ◽  
Ambient Temperature ◽  
Grain Growth ◽  
Driving Forces ◽  
Crystal Defects ◽  
Coarse Grained ◽  
Relaxation Processes ◽  
X Ray Diffraction ◽  
X Ray

The microstructure evolution (crystallite size and microstrain) as well as the residual stress of Cu thin films of various thicknesses (250 nm, 500 nm, and 1 μm) on passivated Si substrates during isochronal annealing was investigated by in situ X-ray diffraction measurements in the temperature range between 25 °C and 250 °C. Before annealing, the thermoelastic behavior was investigated excluding the occurrence of thermally activated relaxation processes occurring above ambient temperature by in situ stress measurements below ambient temperature. On this basis, above ambient temperature, effects of stress relaxation and emerging secondary stresses (due to grain growth and annihilation of crystal defects, giving rise to a considerable tensile stress contribution development) could be identified for all three layers in the temperature regime between ambient temperature and 250 °C. Grain growth in the nanocrystalline thin films started at much lower temperatures as compared to coarse-grained materials. The results were discussed in terms of the effects of different driving forces and grain-boundary mobilities acting in nanocrystalline materials.

Nanoscale stability of two- and three-dimensional defects in Cu/Ag–Mo thin films

2017 ◽  
Vol 50 (1) ◽  
pp. 152-171 ◽  
Author(s):  
G. Csiszár ◽  
A. Makvandi ◽  
E. J. Mittemeijer
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Texture Evolution ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Twin Boundaries ◽  
X Ray ◽  
Transmission Electron ◽  
Before And After ◽  
Columnar Grain

A comparative study of the thermal stability of nanocrystalline Cu–Mo and Ag–Mo alloy thin films was performed. Phase decomposition, texture evolution, grain coarsening and segregation of Mo to planar faults of both films, before and after heat treatment, were studied using X-ray diffraction measurements and (high-resolution) transmission electron microscopy with energy-dispersive spectroscopy. The evolution of stress/strain in the thin films was traced by in situ X-ray diffraction measurements. The segregation of Mo solute atoms at twin boundaries in both films already occurs at room temperature. By first segregation and then precipitation of Mo atoms at grain boundaries, the columnar grain microstructure is preserved upon heat treatment. In the case of Ag–Mo thin films, the twin boundaries are also more or less preserved at elevated temperature, but in the case of Cu–Mo thin films the annihilation of twin boundaries takes place concomitantly with the precipitation of Mo in columnar grain interiors.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

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