The Effect of Cluster Interactions on Electromigration Induced Stress Evolution in Confined Metal Lines

1995 ◽  
Vol 391 ◽  
Author(s):  
D.D. Brown ◽  
J.E. Sanchez ◽  
P.R. Besser ◽  
M.A. Korhonen ◽  
C.-Y. Li
Keyword(s):  
Integrated Circuits ◽  
Grain Boundaries ◽  
Length Distribution ◽  
Diffusion Path ◽  
Line Length ◽  
Segment Length ◽  
Stress Profile ◽  
Fast Diffusion ◽  
Metal Interconnects ◽  
Interconnect Lines

AbstractIn near-bamboo interconnect lines used in advanced integrated circuits, electromigration flux divergences occur at the intersection between polycrystalline cluster segments (where grain boundaries offer a fast diffusion path), and bamboo segments (where there are no grain boundaries along the line length). For confined, passivated metal interconnects, these flux divergences are linked to the evolution of significant mechanical stresses in the metal. A quasisteady state stress distribution builds up relatively quickly in the cluster segments and remains unchanged until there is significant diffusion into the bamboo segments. The stress profile of a given cluster then becomes dependent on neighboring clusters as well as the diffusivity and flux in the separating bamboo segments. Previous analyses of electromigration failure in interconnect lines have focused on the distribution of cluster lengths and the stress build up in isolated cluster segments. In this paper, we show that the bamboo length distribution can strongly affect the interaction between clusters and the evolution of stresses in a near-bamboo interconnect during electromigration. We present simulation results, using a ratio of cluster to bamboo diffusivity Dc/Db=100, which show greater interactions and larger maximum stresses in cluster segments as the average bamboo segment length decreases and as the bamboo segment length distribution widens.

Crystallographic Texture Characterization of Inlaid Copper Interconnects

2001 ◽  
Vol 672 ◽  
Author(s):  
Inka Zienert ◽  
Paul Besser ◽  
Werner Blum ◽  
Ehrenfried Zschech
Keyword(s):  
Integrated Circuits ◽  
Diffusion Path ◽  
Copper Interconnects ◽  
Fast Diffusion ◽  
High Angle ◽  
Current Densities ◽  
Interconnect Lines ◽  
Texture Characterization ◽  
Interconnect System

Developing faster integrated circuits places incredible demands on the interconnect system. The smaller feature sizes lead to excessive current densities, which in turn make the interconnect lines more susceptible to electromigration (EM) failure.[1] Studies have shown that EM performance can be improved by increasing the strength of the {111} texture in conventionally- fabricated aluminum-based lines.[2-6] The strong {111} texture minimizes the presence of high- angle grain boundaries along the interconnect line, thus minimizing a fast-diffusion path for EM mass transport.[2-4,7-12]

scholarly journals Antagonist effects of grain boundaries between the trapping process and the fast diffusion path in nickel bicrystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Li ◽  
A. Hallil ◽  
A. Metsue ◽  
A. Oudriss ◽  
J. Bouhattate ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Hydrogen Diffusion ◽  
Short Circuit ◽  
Diffusion Path ◽  
Fast Diffusion ◽  
Fundamental Parameters ◽  
Segregation Energy ◽  
Atomistic Calculations ◽  
And Migration ◽  
Trapping Process

AbstractHydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features in understanding hydrogen embrittlement in a large variety of common engineer situations. These interactions implicate some fundamental processes classified as segregation, trapping and diffusion of the solute which can be studied as a function of grain boundary configuration. In the present study, we carried out an extensive analysis of four grain-boundaries based on the complementary of atomistic calculations and experimental data. We demonstrate that elastic deformation has an important contribution on the segregation energy which cannot be simply reduced to a volume change and need to consider the deviatoric part of strain. Additionally, some significant configurations of the segregation energy depend on the long-range elastic distortion and allows to rationalize the elastic contribution in three terms. By investigating the different energy barriers involved to reach all the segregation sites, the antagonist impact of grain boundaries on hydrogen diffusion and trapping process was elucidated. The segregation energy and migration energy are two fundamental parameters in order to classify the grain-boundaries as a trapping location or short circuit for diffusion.

scholarly journals Some Advances on Antagonist Effects of Grain Boundaries between the Trapping Process and the Fast Diffusion Path Investigated on Nickel Bicrystals

2021 ◽  
Author(s):  
xavier FEAUGAS ◽  
jiaqi Li ◽  
Malek Hallil ◽  
Arnaud Metsue ◽  
Abdelali Oudriss ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Hydrogen Diffusion ◽  
Short Circuit ◽  
Diffusion Path ◽  
Fast Diffusion ◽  
Fundamental Parameters ◽  
Segregation Energy ◽  
Atomistic Calculations ◽  
And Migration ◽  
Trapping Process

Abstract Hydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features in understanding hydrogen embrittlement in a large variety of common engineer situations. These interactions implicate some fundamental processes classified as segregation, trapping and diffusion of the solute which can be studied as a function of grain boundary configuration. In the present study, we carried out an extensive analysis of four grain-boundaries based on the complementary of atomistic calculations and experimental data. We demonstrate that elastic deformation has an important contribution on the segregation energy which cannot be simply reduced to a volume change and need to consider the deviatoric part of strain. Additionally, some significant configurations of the segregation energy depend on the long-range elastic distortion and allows to rationalize the elastic contribution in three terms. By investigating the different energy barriers involved to reach all the segregation sites, the antagonist impact of grain boundaries on hydrogen diffusion and trapping process was elucidated. The segregation energy and migration energy are two fundamental parameters in order to classify the grain-boundaries as a trapping location or short circuit for diffusion.

Analytical electron microscopy of grain boundaries in Al-Cu metallizations

1992 ◽  
Vol 50 (2) ◽  
pp. 1684-1685
Author(s):  
J. R. Michael ◽  
A. D. Romig ◽  
D. R. Frear
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuits ◽  
Failure Mode ◽  
Current Density ◽  
Thermal History ◽  
Analytical Electron Microscopy ◽  
Cu Metallization ◽  
Analytical Electron ◽  
Interconnect Lines

Al with additions of Cu is commonly used as the conductor metallizations for integrated circuits, the Cu being added since it improves resistance to electromigration failure. As linewidths decrease to submicrometer dimensions, the current density carried by the interconnect increases dramatically and the probability of electromigration failure increases. To increase the robustness of the interconnect lines to this failure mode, an understanding of the mechanism by which Cu improves resistance to electromigration is needed. A number of theories have been proposed to account for role of Cu on electromigration behavior and many of the theories are dependent of the elemental Cu distribution in the interconnect line. However, there is an incomplete understanding of the distribution of Cu within the Al interconnect as a function of thermal history. In order to understand the role of Cu in reducing electromigration failures better, it is important to characterize the Cu distribution within the microstructure of the Al-Cu metallization.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

scholarly journals A Chromosome-Based Model for Estimating the Number of Conserved Segments Between Pairs of Species From Comparative Genetic Maps

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 323-332
Author(s):  
David Waddington ◽  
Anthea J Springbett ◽  
David W Burt
Keyword(s):  
Maximum Likelihood ◽  
Dna Sequences ◽  
Common Ancestor ◽  
Length Distribution ◽  
Genetic Maps ◽  
Segment Length ◽  
Syntenic Block ◽  
Comparative Maps

Abstract Comparative genetic maps of two species allow insights into the rearrangements of their genomes since divergence from a common ancestor. When the map details the positions of genes (or any set of orthologous DNA sequences) on chromosomes, syntenic blocks of one or more genes may be identified and used, with appropriate models, to estimate the number of chromosomal segments with conserved content conserved between species. We propose a model for the distribution of the lengths of unobserved segments on each chromosome that allows for widely differing chromosome lengths. The model uses as data either the counts of genes in a syntenic block or the distance between extreme members of a block, or both. The parameters of the proposed segment length distribution, estimated by maximum likelihood, give predictions of the number of conserved segments per chromosome. The model is applied to data from two comparative maps for the chicken, one with human and one with mouse.

Single-Crystalline and Bamboo Al Lines Fabricated by Graphoepitaxy: Microstructure and 1/f Noise Measurements

1996 ◽  
Vol 428 ◽  
Author(s):  
Marc J.C. Van Den Homberg ◽  
A. H. Verbruggen ◽  
P. F. A. Alkemade ◽  
S. Radelaar
Keyword(s):  
Integrated Circuits ◽  
Grain Boundaries ◽  
Low Noise ◽  
Dc Magnetron Sputtering ◽  
Rapid Thermal Anneal ◽  
Single Crystalline ◽  
Noise Measurements ◽  
Scaling Down ◽  
Sputter Deposited

AbstractThe continuing scaling-down of integrated circuits leads to increased metallization reliability problems, especially electromigration. We used 1/f noise measurements to study the relation between electromigration and microstructure. These measurements are very sensitive to the microstructural attributes, such as grain boundaries and dislocations. Al lines were grown by graphoepitaxy: First, a pure Al film was grown by dc magnetron sputtering on a groove pattern etched into a SiO2 substrate. The growth was then followed by an in situ rapid thermal anneal that resulted in a complete filling of the grooves with Al. These Al lines were carefully characterized with SEM and Backscatter Kikuchi Diffraction. Depending on the presence of a temperature gradient during the anneal, the lines were either nearly single-crystalline or bamboo with one grain per ∼ 3 μm. The resistivity was ∼ 2.8 μΩcm, only slightly higher than for bulk Al. We measured the 1/f noise with the two-channel ac technique at RT. We found in both bamboo as well as the single-crystalline lines a very low noise intensity; a factor two lower than in conventionally sputter deposited and annealed Al lines. No clear difference between the noise spectra of the bamboo and the single-crystalline lines was observed. We concluded that grain boundaries are not the only contributor to 1/f noise; other types of defects must play a role as well.

scholarly journals Investigation on the Corrosion Behavior of Lean Duplex Stainless Steel 2404 after Aging within the 650–850 °C Temperature Range

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 529 ◽  
Author(s):  
Federica Zanotto ◽  
Vincenzo Grassi ◽  
Andrea Balbo ◽  
Fabrizio Zucchi ◽  
Cecilia Monticelli
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Thermal Aging ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Localized Corrosion ◽  
Fast Diffusion ◽  
Lean Duplex Stainless Steel

This paper reports the effects of thermal aging between 650 and 850 °C on the localized corrosion behavior of lean duplex stainless steel (LDSS 2404). Critical pitting temperature (CPT) and double loop electrochemical potentiokinetic reactivation (DL-EPR) tests were performed. The localization of pitting attack and intergranular corrosion (IGC) attack after DL-EPR was investigated by optical (OM) and scanning electron microscopy (SEM) and by focused ion beam (FIB) coupled to SEM. Thermal aging caused the precipitation of mainly chromium nitrides at grain boundaries. Aging at 650 °C or short aging times (5 min) at 750 °C caused nitride precipitation mainly at α/α grain boundaries as a result of fast diffusion of chromium in this phase. Aging at 850 °C or aging times from 10 to 60 min at 750 °C also allowed the precipitation at the α/γ interface. Nitrides at γ/γ grain boundaries were observed rarely and only after long aging times (60 min) at 850 °C. Electrochemical tests showed that in as-received samples, pitting attack only affected the α phase. Conversely, in aged samples, pitting and IGC attack were detected close to nitrides in correspondence of α/α and α/γ grain boundaries depending on aging temperatures and times.

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