Local Microstructure and Stress in Al(Cu) Thin Film Structures Studied by X-Ray Microdiffraction

2001 ◽  
Vol 673 ◽  
Author(s):  
B.C. Valek ◽  
N. Tamura ◽  
R. Spolenak ◽  
A.A. MacDowell ◽  
R.S. Celestre ◽  
...  
Keyword(s):  
Thin Film ◽  
Integrated Circuits ◽  
Local Stress ◽  
Local Strain ◽  
Temperature Cycle ◽  
X Ray ◽  
Cu Thin Film ◽  
Individual Grains ◽  
Interconnect Lines ◽  
Stress Variations

ABSTRACTThe microstructure of materials (grain orientation, grain boundaries, grain size distribution, local strain/stress gradients, defects, …) is very important in defining the electromigration resistance of interconnect lines in modern integrated circuits. Recently, techniques have been developed for using submicrometer focused white and monochromatic x-ray beams at synchrotrons to obtain local orientation and strain information within individual grains of thin film materials. In this work, we use the x-ray microdiffraction beam line (7.3.3) at the Advanced Light Source to map the orientation and local stress variations in passivated Al(Cu) test structures (width: 0.7, 4.1 μm) as well as in Al(Cu) blanket films. The temperature effects on microstructure and stress were studied in those same structures by in-situ orientation and stress mapping during a temperature cycle between 25°C and 345°C. Results show large local variations in the different stress components which significantly depart from their average values obtained by more conventional techniques, yet the average stresses in both cases agree well. Possible reasons for these variations will be discussed.

A Novel Technique to Determine Elastic Constants of Thin Films

2008 ◽  
Vol 1139 ◽  
Author(s):  
Klaus Martinschitz ◽  
Rostislav Daniel ◽  
Christian Mitterer ◽  
Keckes Jozef
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Elastic Moduli ◽  
Elastic Anisotropy ◽  
Interaction Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anisotropic Factor ◽  
Polycrystalline Thin Films ◽  
Cu Thin Film

AbstractA new X-ray diffraction technique to determine elastic moduli of polycrystalline thin films deposited on monocrystalline substrates is demonstrated. The technique is based on the combination of sin2ψ and X-ray diffraction wafer curvature techniques which are used to characterize X-ray elastic strains and macroscopic stress in thin film. The strain measurements must be performed for various hkl reflections. The stresses are determined from the substrate curvature applying the Stoney's equation. The stress and strain values are used to calculate hkl reflection dependent X-ray elastic moduli. The mechanical elastic moduli can be then extrapolated from X-ray elastic moduli considering film macroscopic elastic anisotropy. The derived approach shows for which reflection and corresponding value of the X-ray anisotropic factor Γ the X-ray elastic moduli are equal to their mechanical counterparts in the case of fibre textured cubic polycrystalline aggregates. The approach is independent of the crystal elastic anisotropy and depends on the fibre texture type, the texture sharpness, the amount of randomly oriented crystallites and on the supposed grain interaction model. The new method is demonstrated on a fiber textured Cu thin film deposited on monocrystalline Si(100) substrate. The advantage of the new technique remains in the fact that moduli are determined non-destructively, using a static diffraction experiment and represent volume averaged quantities.

Determination of the Mechanical Response of Thin Films with X-Rays

1993 ◽  
Vol 308 ◽  
Author(s):  
I. C. Noyan ◽  
G. Sheikh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Response ◽  
Strain Analysis ◽  
Local Strain ◽  
X Rays ◽  
Stress Strain ◽  
X Ray ◽  
The Individual

ABSTRACTThe mechanical response of a specimen incorporating thin films is dictated by a combination of fundamental mechanical parameters such as Young's moduli of the individual layers, and by configurational parameters such as adhesion strength at the interface(s), residual stress distribution and other process dependent factors. In most systems, the overall response will be dominated by the properties of the (much thicker) substrate. Failure within the individual layers, on the other hand, is dependent on the local strain distributions and can not be predicted from the substrate values alone. To better understand the mechanical response of these systems, the strain within the individual layers of the thin film system must be measured and correlated with applied stresses. Phase selectivity of X-ray stress/strain analysis techniques is well suited for this purpose. In this paper, we will review the use of the traditional x-ray stress/strain analysis methods for the determination of the mechanical properties of thin film systems.

Mapping local strain in thin film/substrate systems using x-ray microdiffraction topography

2007 ◽  
Vol 90 (9) ◽  
pp. 091918 ◽  
Author(s):  
Hanfei Yan ◽  
Conal E. Murray ◽  
I. C. Noyan
Keyword(s):  
Thin Film ◽  
Local Strain ◽  
X Ray ◽  
Film Substrate

scholarly journals In-situ early stage electromigration study in Al line using synchrotron polychromatic X-ray microdiffraction

2008 ◽  
Vol 1079 ◽  
Author(s):  
Kai Chen ◽  
N. Tamura ◽  
K. N. Tu
Keyword(s):  
Electric Current ◽  
Early Stage ◽  
Shape Change ◽  
Present Report ◽  
Semiconductor Industry ◽  
X Ray ◽  
Cu Interconnect ◽  
Individual Grains ◽  
Interconnect Lines

ABSTRACTElectromigration is a phenomenon that has attracted much attention in the semiconductor industry because of its deleterious effects on electronic devices (such as interconnects) as they become smaller and current density passing through them increases. However, the effect of the electric current on the microstructure of interconnect lines during the very early stage of electromigration is not well documented. In the present report, we used synchrotron radiation based polychromatic X-ray microdiffraction for the in-situ study of the electromigration induced plasticity effects on individual grains of an Al (Cu) interconnect test structure. Dislocation slips which are activated by the electric current stressing are analyzed by the shape change of the diffraction peaks. The study shows polygonization of the grains due to the rearrangement of geometrically necessary dislocations (GND) in the direction of the current. Consequences of these findings are discussed.

Strain and Texture in Al-Interconnect Wires Weasured by X-Xay Microbeam Diffraction

1999 ◽  
Vol 563 ◽  
Author(s):  
Nobumichi Tamura ◽  
J.-S. Chung ◽  
G. E. Ice ◽  
B. C. Larson ◽  
J. D. Budai ◽  
...  
Keyword(s):  
Local Strain ◽  
Beam Line ◽  
Strain Measurements ◽  
X Ray ◽  
Intergranular Strain ◽  
White Beam ◽  
Individual Grains ◽  
Photon Source

AbstractThe local strain and texture in Al interconnect wires have been investigated using white and monochromatic x-ray microbeams on the MHATTCAT undulator beam line at the Advanced Photon Source. Intergrain and intragrain orientations were obtained with ∼0.01° sensitivity using white beam measurements on wide Al pads (∼100 μm) and thin (2 μm) Al wires. Orientation changes of up to 1°were found within individual grains of the (111) textured Al interconnects. Deviatoric strain measurements indicate small intragranular strain variations, but intergranular strain variations were found to be quite large.

Grain Boundary Chemistry in Al-Cu Metallizations as Determined by Analytical Electron Microscopy

1991 ◽  
Vol 229 ◽  
Author(s):  
J. R. Michael ◽  
A. D. Romig ◽  
D. R. Frear
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuits ◽  
Grain Boundary ◽  
Analytical Electron Microscopy ◽  
Second Phase ◽  
Collector Plate ◽  
Analytical Electron ◽  
Cu Thin Film ◽  
Boundary Chemistry ◽  
Interconnect Lines

AbstractAl with additions of Cu is commonly used as the conductor metallizations for integrated circuits (ICs). As the packing density of ICs increases, interconnect lines are required to carry ever higher current densities. Consequently, reliability due to electromigration failure becomes an increasing concern. Cu has been found to increase the lifetimes of these conductors, but the mechanism by which electromigration is improved is not yet fully understood. In order to evaluate certain theories of electromigration it is necessary to have a detailed description of the Cu distribution in the Al microstructure, with emphasis on the distribution of Cu at the grain boundaries. In this study analytical electron microscopy (AEM) has been used to characterize grain boundary regions in an Al-2 wt.% Cu thin film metallization on Si after a variety of thermal treatments. The results of this study indicate that the Cu distribution is dependent on the thermal annealing conditions. At temperatures near the θ phase (CuAl2) solvus, the Cu distribution may be modelled by the collector plate mechanism, in which the grain boundary is depleted in Cu relative to the matrix. At lower temperatures, Cu enrichment of the boundaries occurs, perhaps as a precursor to second phase formation. Natural cooling from the single phase field produces only grain boundary depletion of Cu consistent with the collector-plate mechanism. The kinetic details of the elemental segregation behavior derived from this study can be used to describe microstructural evolution in actual interconnect alloys.

Electromigration-Induced Plastic Deformation in Cu Damascene Interconnect Lines as Revealed by Synchrotron X-Ray Microdiffraction

2006 ◽  
Vol 914 ◽  
Author(s):  
Arief Budiman ◽  
N. Tamura ◽  
B. C. Valek ◽  
K. Gadre ◽  
J. Maiz ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Rotation Axis ◽  
Practical Implication ◽  
Electron Flow ◽  
Plastic Behavior ◽  
Grain Rotation ◽  
X Ray ◽  
Cu Interconnect ◽  
Individual Grains ◽  
Interconnect Lines

AbstractThe Scanning X-Ray Submicron Diffraction (μ-SXRD) technique using focused synchrotron radiation white beam developed in the Beamline 7.3.3 at the ALS Berkeley Lab has been used to study the microstructural evolution at granular level of Cu polycrystalline lines during electromigration. Plastic deformation was observed in damascene Cu interconnect test structures during this in situ electromigration experiment and before the onset of visible microstructural damage (voiding, hillock formation). We show here that the extent of this electromigration-induced plasticity is dependent on the line width. In wide lines, plastic deformation manifests itself as grain bending and the formation of subgrain structures, while only grain rotation is observed in the narrower lines. The analysis of the Laue reflections allow for the determination of the geometrically necessary dislocation density in individual grains as well as for the misorientation angles between small angle boundaries generated by polygonization. The deformation geometry leads us to conclude that dislocations introduced by plastic flow lie predominantly in the direction of electron flow and may provide additional easy paths for the transport of point defects. Furthermore, we observe that the rotation axis of this plastic deformation coincides with one of the <112> line directions of the known slip systems for FCC crystal, and that it is always very close (within a few degrees) to the direction of the electron flow. This finding suggests a correlation of the proximity of certain <112> line directions to the direction of electron flow with the occurrence of plastic behavior. One important practical implication of this particular finding is that the grain texture of the line might thus play an important role in giving higher resistance towards early plastic response of the Cu line upon the electromigration loading.

X-ray Absorption Spectroscopy Investigation of the Sub-Nanoscale Strain in Thin-Film Lithium Ion Battery Cathodes

2004 ◽  
Vol 822 ◽  
Author(s):  
Faisal M. Alamgir ◽  
Jason Vansluytman ◽  
Daniel Carter ◽  
Jay Whitacre ◽  
Chi-Chang Kao ◽  
...  
Keyword(s):  
Thin Film ◽  
Absorption Spectroscopy ◽  
Rotational Symmetry ◽  
Lithium Ion ◽  
Local Strain ◽  
Intrinsic Stress ◽  
Structural Defects ◽  
X Ray ◽  
Metal Metal ◽  
X Ray Absorption

AbstractLiCoO2 and LiNiO2, two important cathode materials for Li-ion batteries, were studied in their respective bulk and thin-film form. X-ray absorption spectroscopy (XAS) has been used to probe the local atomic structure and structural defects in the thin-film and bulk cathodes. Results comparing Li(Co,Ni)O2 in the bulk and thin-film forms suggests a correlation between intrinsic stress and local strain in the thin-film. This local strain is manifested by a collapse of the six-fold rotational symmetry within the metal-metal layer of the Li(Co,Ni)O2 system into a two fold one. The relationship between annealing conditions and the resulting local strain in these films is examined.

scholarly journals Investigation of synchrotron X-ray induced oxidation of Ag–Cu thin-film

2020 ◽  
Vol 272 ◽  
pp. 127843 ◽  
Author(s):  
Jian Hui ◽  
Hengrui Zhang ◽  
Qingyun Hu ◽  
Zhan Zhang ◽  
Yang Ren ◽  
...  
Keyword(s):  
Thin Film ◽  
X Ray ◽  
Cu Thin Film

scholarly journals Grain Orientation Mapping of Passivated Aluminum Interconnect Lines with X-ray Micro-Diffraction

1998 ◽  
Vol 524 ◽  
Author(s):  
A. A. MacDowell ◽  
C. H. Chang ◽  
H. A. Padmore ◽  
J. R. Patel ◽  
A. C. Thompson
Keyword(s):  
Grain Orientation ◽  
Grazing Incidence ◽  
Line Length ◽  
Laue Pattern ◽  
X Ray Diffraction ◽  
X Ray ◽  
Orientation Mapping ◽  
Future Direction ◽  
Individual Grains ◽  
Interconnect Lines

ABSTRACTA micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-μm size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6-14 keV or monochromatic generated from a pair of channel cut crystals. A Laue diffraction pattern from a single grain in a passivated 2-μm wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of a few seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedures used are described, as is a grain orientation result. The future direction of this program is discussed in the context of strain measurements in the area of electromigration.

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