J. Bravman | Bucknell University (original) (raw)

Papers by J. Bravman

Research paper thumbnail of Quantitative Characterization of Dislocation Structure coupled with Electromigration in a Passivated Al (0.5wt%Cu) Interconnects

MRS Proceedings, 2003

New synchrotron x-ray microbeam methodology is used to analyze and test the reliability of interc... more New synchrotron x-ray microbeam methodology is used to analyze and test the reliability of interconnects. The early stage of plastic deformation induced by electromigration before any damages become visible has been recently revealed by white beam scanning X-ray microdiffraction during an accelerated test on Al interconnect lines. In the present paper, we provide a quantitative analysis of the dislocation structure generated in several micron-sized Al grains in both the middle region and ends of the interconnect line during an in-situ electromigration experiment. We demonstrate that the evolution of the dislocation structure during electromigration is highly inhomogeneous and results in the formation of randomly distributed geometrically necessary dislocations as well as geometrically necessary boundaries. The orientation of the activated slip systems and rotation axis depends on the position of the grain in the interconnect line. The origin of the observed plastic deformation is co...

Research paper thumbnail of Thermal activation of vortex motion inYBa2Cu3O7−δfilms at low temperatures

Physical Review B, 1991

Thermally activated Aux vortex motion in a constant applied field is studied at temperatures betw... more Thermally activated Aux vortex motion in a constant applied field is studied at temperatures between 2.5 and 21 K for In situ thin films of YBa2Cu307 z. The magnitude and temperature dependence of the dissipation is shown to be consistent with an activation energy U(J), which is independent of temperature in this temperature region, but which is assumed to be a function only of current J. Activation energies U(J) are deduced for currents between 1X 10' and 2. 5 X 10' 2/cm for the samples measured, by considering the change in the decay rate, at constant current, as a function of temperature. These results indicate that the fundamental mechanism for dissipation in this temperature range is thermally activated.

Research paper thumbnail of Transport characterization of calcium-dopedYBa2Cu3O7−δthin films

Physical Review B, 1995

We report systematic studies of the normal-state conductivity and thermopower of epitaxial Yi Ca ... more We report systematic studies of the normal-state conductivity and thermopower of epitaxial Yi Ca Ba2Cu307 p thin films with 0 & x & 0.3 as a function of oxygen content. The superconducting transition temperature T is found to be parabolic in conductivity o. for each sample, with a universal scaling behavior for all 6lms with z & 0.2. The room-temperature thermopower, Sz» K, follows the universal correlation between T, and S$95 K reported by S. D. Obertelli et al. [Phys. Rev. B 46, 14 928 (1992)j for all films studied, despite the reduction in maximum T, with increasing calcium content. The thermopower is found to be superior to the conductivity as a measure of the hole concentration because of its reduced sensitivity to extrinsic contributions such as grain boundaries. By assuming that all the charge from oxygen deficiencies. and Ca substitution is transferred to the Cu-0 planes, and by using Obertelli s empirically-derived expression for hole concentration, we show that S295 K can be used to determine the oxygen content of the Alms. The equilibrium oxygen content is found to be reduced to compensate for the additional carriers introduced by Ca substitution in these films, just as has been previously observed in bulk Yi Ca Ba&Cu307-$.

Research paper thumbnail of Nucleation and growth mechanisms of a , b -axis-oriented YBa 2 Cu 3 O 7 − δ films on LaAlO 3

Physical Review B, 1993

The initial stages of deposition of a,b-axis-oriented YBa2Cu3O7-delta onto LaAlO3 substrates have... more The initial stages of deposition of a,b-axis-oriented YBa2Cu3O7-delta onto LaAlO3 substrates have been examined using transmission-electron microscopy. These films have their c axis parallel to the plane of the substrate throughout their thickness, including at the film-substrate interface: no initial layer with the c axis perpendicular to the plane of the substrate is observed. Nucleation of the c-parallel material is extremely dense, such that the triple perovskite layering along the c axis is sometimes disrupted, leading to structures containing two or four perovskite blocks instead of the usual three. By a film thickness of 8 nm the proper YBa2Cu3O7-delta structure has stabilized, although the domain size is still very small, on the order of four unit cells in the c^ direction, or 4.7 nm. Two ledge structures are observed in projection on the film surface: (100)/(001) faces and (110)/(013) faces.

Research paper thumbnail of Reduction of the magnetization decay rate in high- T c superconductors

Physical Review B, 1990

Small decrements in the temperature {Delta}T of superconducting samples in the critical state are... more Small decrements in the temperature {Delta}T of superconducting samples in the critical state are shown to cause substantial reduction in the rate of magnetic relaxation. Quantitative agreement is obtained between experimental data and a model, which assumes the decay of the supercurrent subsequent to the change in temperature can be described in terms of the critical state. Experiments were performed in an applied field of 5.07 kG, on thick film (1.6 {mu}m) samples which generate a substantial self-field ({similar to}5 kG). The effect of temperature reduction is shown to be calculable from a knowledge of the decay-rate exponent {ital n} and {ital J}{sub {ital c}}(T) in the relevant temperature range. These results indicate that cooling in the critical state can be used to study magnetization decay at current densities reduced from the critical current.

Research paper thumbnail of Coupling Between Precipitation and Plastic Deformation During Electromigration in a Passivated Al (0.5wt%Cu) Interconnect

MRS Proceedings, 2004

In the present paper the evolution of the dislocation structure during electromigration in differ... more In the present paper the evolution of the dislocation structure during electromigration in different regions along the Al(Cu) interconnect line is considered. It is shown that plastic deformation increases in the regions close to cathode end of the interconnect line. A coupling between the dissolution, growth and re-precipitation of Al2Cu precipitates and the electromigration-induced plastic deformation of grains in interconnects is observed. Possible mechanism of the Cu doping effect on the improved electromigration resistance of the Al(Cu) interconnects is discussed.

Research paper thumbnail of Design and fabrication of a monolithic high-density probe card for high-frequency on-wafer testing

International Technical Digest on Electron Devices Meeting

Abstract A novel probe card structure for high-density, high-frequency applications is described.... more Abstract A novel probe card structure for high-density, high-frequency applications is described. Conventional probe tips are replaced by compliant, multilayer cantilever beams fabricated monolithically on a silicon wafer, which, if desired, can include active circuitry ...

Research paper thumbnail of Grain Orientation and Strain Measurements in Sub-Micron wide Passivated Individual Aluminum Test Structures

MRS Proceedings, 2000

An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities... more An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities, has been built at the Advanced Light Source. The purpose of this beamline is to address the myriad problems in Materials Science and Physics that require submicron x-ray beams for structural characterization. Many such problems are found in the general area of thin films and nano-materials. For instance, the ability to characterize the orientation and strain state in individual grains of thin films allows us to measure structural changes at a very local level. These microstructural changes are influenced heavily by such parameters as deposition conditions and subsequent treatment. The accurate measurement of strain gradients at the micron and sub-micron level finds many applications ranging from the strain state under nano-indenters to gradients at crack tips. Undoubtedly many other applications will unfold in the future as we gain experience with the capabilities and limitations of th...

Research paper thumbnail of Vortex pinning and twin boundaries in YBa 2 Cu 3 O 7 − δ thin films

Physical Review B, 1990

The interaction between magnetic flux vortices and twin boundaries is investigated in YBa{sub 2}C... more The interaction between magnetic flux vortices and twin boundaries is investigated in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films. Films grown to various thicknesses, and cooled along different paths in the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} phase diagram, are shown to have various twin boundary microstructures and densities. It is demonstrated that changes in processing result in differences in the vortex-pinning behavior of the films, but that these differences are not due to changes in the microstructure of the twin boundaries. Further, observed differences in the twin spacing do not result in changes in the volume pinning force. This is found to be true in the magnetic-field regime spanning the range from where the flux vortex spacing is large relative to the twin density to where the vortex spacing is small relative to this density.

Research paper thumbnail of Proceedings of specimen preparation for transmission electron microscopy of materials. 3

Transmission electron microscopy is well established as a tool for both fundamental and applied r... more Transmission electron microscopy is well established as a tool for both fundamental and applied research. From the earliest applications in the physical sciences to the most recent studies, TEM techniques have contributed greatly to our understanding of the structure and properties of materials. TEM analysis is a common thread in virtually all of the symposia organized by the Materials Research

Research paper thumbnail of Local Plasticity of Al Thin Films as Revealed by X-Ray Microdiffraction

Physical Review Letters, 2003

Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective leng... more Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective length scales smaller than the grain size. We have measured large strain distributions and their changes under plastic strain in 1.5-microm-thick Al 0.5% Cu films using a 0.8-microm-diameter white x-ray probe at the Advanced Light Source. Strain distributions arise not only from the distribution of grain sizes and orientation, but also from the differences in grain shape and from stress environment. Multiple active glide plane domains have been found within single grains. Large grains behave like multiple smaller grains even before a dislocation substructure can evolve.

Research paper thumbnail of Vortex motion and time dependent magnetic responses in high Tc superconductors

Physica C: Superconductivity, 1989

Research paper thumbnail of Use of angle resolved x-ray photoelectron spectroscopy for determination of depth and thickness of compound layer structures

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2001

... with respect to the surface, K is an instrumental constant taking into account the mea-sureme... more ... with respect to the surface, K is an instrumental constant taking into account the mea-surement time, the collection efficiency of the analyzer, sample roughness, etc., F(θ) is the effective flux of incident x-ray radiation mea-sured as photons ... Fi(θ) ARi(θ) ΣiARi(θ) 0 ni(u)e udu, (3a) ...

Research paper thumbnail of Grain orientation and strain measurements in micron wide passivated individual Al and Cu test structures

Research paper thumbnail of Scanning X-ray microdiffraction with submicrometer white beam for strain/stress and orientation mapping in thin films

Journal of Synchrotron Radiation, 2003

The technique of white beam Scanning X-ray Microdiffraction when applied to samples consisting of... more The technique of white beam Scanning X-ray Microdiffraction when applied to samples consisting of multiple micro-grains is described in detail. The application to two samples of thin-film metals is given.

Research paper thumbnail of Thin films: stresses and mechanical properties V: symposium held November 28-December 2, 1994, Boston, Massachusetts, USA

Research paper thumbnail of Effect of encapsulant material on the diffusion of beryllium in molecular beam epitaxy gallium arsenide

Applied Physics Letters, 1996

ABSTRACT Experiments were done that illustrate the role of the wafer surface in the transient dif... more ABSTRACT Experiments were done that illustrate the role of the wafer surface in the transient diffusion of Be in GaAs. Samples were doped during molecular beam epitaxial growth and annealed at 900 °C for 15 min and 2 h under two different caps. In some of the annealed samples, the dopant was initially located near the surface. Other samples had the dopant initially located in a buried layer. Both types of samples were analyzed by secondary ion mass spectrometry measurement. The variations in the diffusion behavior for these different experimental conditions can all be qualitatively explained by a model which accounts for three important effects: the transient evolution of point defect populations; the injection of Ga vacancies by an oxide cap; and the efficiency of the surface in restoring point defect equilibria. © 1996 American Institute of Physics.

Research paper thumbnail of High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

Applied Physics Letters, 2002

The availability of high brilliance synchrotron sources, coupled with recent progress in achromat... more The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop a X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

Research paper thumbnail of Specimen preparation for transmission electron microscopy of materials III : symposium held December 5-6, 1991, Boston, Mass., U.S.A

: Successful TEM experimentation depends on many things, one being specimen preparation. Whereas ... more : Successful TEM experimentation depends on many things, one being specimen preparation. Whereas TEM samples of bulk metallic or ceramic materials can often be fabricated in quite straightforward manner, the need to examine non-bulk and/or other classes of materials creates a need for more specialized preparation techniques. This need is addressed in the present volume, in which more than 45 papers covering both general and materials-specific methods are described. Metallic, polymeric, plastic, semiconducting, ceramic, and magnetic materials, as found in bulk, thin film, dispersed and powdered forms are discussed. Keywords: Transmission electron microscopy; Specimen Preparation; Semiconductors; Ceramics; Polymers; Metals; Magnetic materials.

Research paper thumbnail of Structural and electrical characterization of LPCVD tungsten contacts to silicon

Research paper thumbnail of Quantitative Characterization of Dislocation Structure coupled with Electromigration in a Passivated Al (0.5wt%Cu) Interconnects

MRS Proceedings, 2003

New synchrotron x-ray microbeam methodology is used to analyze and test the reliability of interc... more New synchrotron x-ray microbeam methodology is used to analyze and test the reliability of interconnects. The early stage of plastic deformation induced by electromigration before any damages become visible has been recently revealed by white beam scanning X-ray microdiffraction during an accelerated test on Al interconnect lines. In the present paper, we provide a quantitative analysis of the dislocation structure generated in several micron-sized Al grains in both the middle region and ends of the interconnect line during an in-situ electromigration experiment. We demonstrate that the evolution of the dislocation structure during electromigration is highly inhomogeneous and results in the formation of randomly distributed geometrically necessary dislocations as well as geometrically necessary boundaries. The orientation of the activated slip systems and rotation axis depends on the position of the grain in the interconnect line. The origin of the observed plastic deformation is co...

Research paper thumbnail of Thermal activation of vortex motion inYBa2Cu3O7−δfilms at low temperatures

Physical Review B, 1991

Thermally activated Aux vortex motion in a constant applied field is studied at temperatures betw... more Thermally activated Aux vortex motion in a constant applied field is studied at temperatures between 2.5 and 21 K for In situ thin films of YBa2Cu307 z. The magnitude and temperature dependence of the dissipation is shown to be consistent with an activation energy U(J), which is independent of temperature in this temperature region, but which is assumed to be a function only of current J. Activation energies U(J) are deduced for currents between 1X 10' and 2. 5 X 10' 2/cm for the samples measured, by considering the change in the decay rate, at constant current, as a function of temperature. These results indicate that the fundamental mechanism for dissipation in this temperature range is thermally activated.

Research paper thumbnail of Transport characterization of calcium-dopedYBa2Cu3O7−δthin films

Physical Review B, 1995

We report systematic studies of the normal-state conductivity and thermopower of epitaxial Yi Ca ... more We report systematic studies of the normal-state conductivity and thermopower of epitaxial Yi Ca Ba2Cu307 p thin films with 0 & x & 0.3 as a function of oxygen content. The superconducting transition temperature T is found to be parabolic in conductivity o. for each sample, with a universal scaling behavior for all 6lms with z & 0.2. The room-temperature thermopower, Sz» K, follows the universal correlation between T, and S$95 K reported by S. D. Obertelli et al. [Phys. Rev. B 46, 14 928 (1992)j for all films studied, despite the reduction in maximum T, with increasing calcium content. The thermopower is found to be superior to the conductivity as a measure of the hole concentration because of its reduced sensitivity to extrinsic contributions such as grain boundaries. By assuming that all the charge from oxygen deficiencies. and Ca substitution is transferred to the Cu-0 planes, and by using Obertelli s empirically-derived expression for hole concentration, we show that S295 K can be used to determine the oxygen content of the Alms. The equilibrium oxygen content is found to be reduced to compensate for the additional carriers introduced by Ca substitution in these films, just as has been previously observed in bulk Yi Ca Ba&Cu307-$.

Research paper thumbnail of Nucleation and growth mechanisms of a , b -axis-oriented YBa 2 Cu 3 O 7 − δ films on LaAlO 3

Physical Review B, 1993

The initial stages of deposition of a,b-axis-oriented YBa2Cu3O7-delta onto LaAlO3 substrates have... more The initial stages of deposition of a,b-axis-oriented YBa2Cu3O7-delta onto LaAlO3 substrates have been examined using transmission-electron microscopy. These films have their c axis parallel to the plane of the substrate throughout their thickness, including at the film-substrate interface: no initial layer with the c axis perpendicular to the plane of the substrate is observed. Nucleation of the c-parallel material is extremely dense, such that the triple perovskite layering along the c axis is sometimes disrupted, leading to structures containing two or four perovskite blocks instead of the usual three. By a film thickness of 8 nm the proper YBa2Cu3O7-delta structure has stabilized, although the domain size is still very small, on the order of four unit cells in the c^ direction, or 4.7 nm. Two ledge structures are observed in projection on the film surface: (100)/(001) faces and (110)/(013) faces.

Research paper thumbnail of Reduction of the magnetization decay rate in high- T c superconductors

Physical Review B, 1990

Small decrements in the temperature {Delta}T of superconducting samples in the critical state are... more Small decrements in the temperature {Delta}T of superconducting samples in the critical state are shown to cause substantial reduction in the rate of magnetic relaxation. Quantitative agreement is obtained between experimental data and a model, which assumes the decay of the supercurrent subsequent to the change in temperature can be described in terms of the critical state. Experiments were performed in an applied field of 5.07 kG, on thick film (1.6 {mu}m) samples which generate a substantial self-field ({similar to}5 kG). The effect of temperature reduction is shown to be calculable from a knowledge of the decay-rate exponent {ital n} and {ital J}{sub {ital c}}(T) in the relevant temperature range. These results indicate that cooling in the critical state can be used to study magnetization decay at current densities reduced from the critical current.

Research paper thumbnail of Coupling Between Precipitation and Plastic Deformation During Electromigration in a Passivated Al (0.5wt%Cu) Interconnect

MRS Proceedings, 2004

In the present paper the evolution of the dislocation structure during electromigration in differ... more In the present paper the evolution of the dislocation structure during electromigration in different regions along the Al(Cu) interconnect line is considered. It is shown that plastic deformation increases in the regions close to cathode end of the interconnect line. A coupling between the dissolution, growth and re-precipitation of Al2Cu precipitates and the electromigration-induced plastic deformation of grains in interconnects is observed. Possible mechanism of the Cu doping effect on the improved electromigration resistance of the Al(Cu) interconnects is discussed.

Research paper thumbnail of Design and fabrication of a monolithic high-density probe card for high-frequency on-wafer testing

International Technical Digest on Electron Devices Meeting

Abstract A novel probe card structure for high-density, high-frequency applications is described.... more Abstract A novel probe card structure for high-density, high-frequency applications is described. Conventional probe tips are replaced by compliant, multilayer cantilever beams fabricated monolithically on a silicon wafer, which, if desired, can include active circuitry ...

Research paper thumbnail of Grain Orientation and Strain Measurements in Sub-Micron wide Passivated Individual Aluminum Test Structures

MRS Proceedings, 2000

An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities... more An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities, has been built at the Advanced Light Source. The purpose of this beamline is to address the myriad problems in Materials Science and Physics that require submicron x-ray beams for structural characterization. Many such problems are found in the general area of thin films and nano-materials. For instance, the ability to characterize the orientation and strain state in individual grains of thin films allows us to measure structural changes at a very local level. These microstructural changes are influenced heavily by such parameters as deposition conditions and subsequent treatment. The accurate measurement of strain gradients at the micron and sub-micron level finds many applications ranging from the strain state under nano-indenters to gradients at crack tips. Undoubtedly many other applications will unfold in the future as we gain experience with the capabilities and limitations of th...

Research paper thumbnail of Vortex pinning and twin boundaries in YBa 2 Cu 3 O 7 − δ thin films

Physical Review B, 1990

The interaction between magnetic flux vortices and twin boundaries is investigated in YBa{sub 2}C... more The interaction between magnetic flux vortices and twin boundaries is investigated in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films. Films grown to various thicknesses, and cooled along different paths in the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} phase diagram, are shown to have various twin boundary microstructures and densities. It is demonstrated that changes in processing result in differences in the vortex-pinning behavior of the films, but that these differences are not due to changes in the microstructure of the twin boundaries. Further, observed differences in the twin spacing do not result in changes in the volume pinning force. This is found to be true in the magnetic-field regime spanning the range from where the flux vortex spacing is large relative to the twin density to where the vortex spacing is small relative to this density.

Research paper thumbnail of Proceedings of specimen preparation for transmission electron microscopy of materials. 3

Transmission electron microscopy is well established as a tool for both fundamental and applied r... more Transmission electron microscopy is well established as a tool for both fundamental and applied research. From the earliest applications in the physical sciences to the most recent studies, TEM techniques have contributed greatly to our understanding of the structure and properties of materials. TEM analysis is a common thread in virtually all of the symposia organized by the Materials Research

Research paper thumbnail of Local Plasticity of Al Thin Films as Revealed by X-Ray Microdiffraction

Physical Review Letters, 2003

Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective leng... more Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective length scales smaller than the grain size. We have measured large strain distributions and their changes under plastic strain in 1.5-microm-thick Al 0.5% Cu films using a 0.8-microm-diameter white x-ray probe at the Advanced Light Source. Strain distributions arise not only from the distribution of grain sizes and orientation, but also from the differences in grain shape and from stress environment. Multiple active glide plane domains have been found within single grains. Large grains behave like multiple smaller grains even before a dislocation substructure can evolve.

Research paper thumbnail of Vortex motion and time dependent magnetic responses in high Tc superconductors

Physica C: Superconductivity, 1989

Research paper thumbnail of Use of angle resolved x-ray photoelectron spectroscopy for determination of depth and thickness of compound layer structures

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2001

... with respect to the surface, K is an instrumental constant taking into account the mea-sureme... more ... with respect to the surface, K is an instrumental constant taking into account the mea-surement time, the collection efficiency of the analyzer, sample roughness, etc., F(θ) is the effective flux of incident x-ray radiation mea-sured as photons ... Fi(θ) ARi(θ) ΣiARi(θ) 0 ni(u)e udu, (3a) ...

Research paper thumbnail of Grain orientation and strain measurements in micron wide passivated individual Al and Cu test structures

Research paper thumbnail of Scanning X-ray microdiffraction with submicrometer white beam for strain/stress and orientation mapping in thin films

Journal of Synchrotron Radiation, 2003

The technique of white beam Scanning X-ray Microdiffraction when applied to samples consisting of... more The technique of white beam Scanning X-ray Microdiffraction when applied to samples consisting of multiple micro-grains is described in detail. The application to two samples of thin-film metals is given.

Research paper thumbnail of Thin films: stresses and mechanical properties V: symposium held November 28-December 2, 1994, Boston, Massachusetts, USA

Research paper thumbnail of Effect of encapsulant material on the diffusion of beryllium in molecular beam epitaxy gallium arsenide

Applied Physics Letters, 1996

ABSTRACT Experiments were done that illustrate the role of the wafer surface in the transient dif... more ABSTRACT Experiments were done that illustrate the role of the wafer surface in the transient diffusion of Be in GaAs. Samples were doped during molecular beam epitaxial growth and annealed at 900 °C for 15 min and 2 h under two different caps. In some of the annealed samples, the dopant was initially located near the surface. Other samples had the dopant initially located in a buried layer. Both types of samples were analyzed by secondary ion mass spectrometry measurement. The variations in the diffusion behavior for these different experimental conditions can all be qualitatively explained by a model which accounts for three important effects: the transient evolution of point defect populations; the injection of Ga vacancies by an oxide cap; and the efficiency of the surface in restoring point defect equilibria. © 1996 American Institute of Physics.

Research paper thumbnail of High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

Applied Physics Letters, 2002

The availability of high brilliance synchrotron sources, coupled with recent progress in achromat... more The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop a X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

Research paper thumbnail of Specimen preparation for transmission electron microscopy of materials III : symposium held December 5-6, 1991, Boston, Mass., U.S.A

: Successful TEM experimentation depends on many things, one being specimen preparation. Whereas ... more : Successful TEM experimentation depends on many things, one being specimen preparation. Whereas TEM samples of bulk metallic or ceramic materials can often be fabricated in quite straightforward manner, the need to examine non-bulk and/or other classes of materials creates a need for more specialized preparation techniques. This need is addressed in the present volume, in which more than 45 papers covering both general and materials-specific methods are described. Metallic, polymeric, plastic, semiconducting, ceramic, and magnetic materials, as found in bulk, thin film, dispersed and powdered forms are discussed. Keywords: Transmission electron microscopy; Specimen Preparation; Semiconductors; Ceramics; Polymers; Metals; Magnetic materials.

Research paper thumbnail of Structural and electrical characterization of LPCVD tungsten contacts to silicon