Electromigration Failure Distributions for Multi-Layer Interconnects as a Function of Line Width: Experiments and Simulation

1996 ◽  
Vol 427 ◽  
Author(s):  
D. D. Brown ◽  
J. E. Sanchez ◽  
V. Pham ◽  
P. R. Besser ◽  
M. A. Korhonen ◽  
...  
Keyword(s):  
Grain Size ◽  
Stress State ◽  
Mechanical Stress ◽  
Line Width ◽  
Void Volume ◽  
Narrow Line ◽  
Failure Times ◽  
Line Widths ◽  
Critical Void

AbstractIn narrow metal lines used for chip level interconnects, the line width can strongly affect the electromigration reliability, typically due to variations in the microstructure and in the mechanical stress state. These variations have a stronger effect as the line width decreases to the order of the metal grain size or less. Electromigration failure distributions were obtained both experimentally and by simulation for realistic interconnect structures with six different line widths, ranging from lμm to 8μm. In order to simulate the electromigration failure distributions, microstructure statistics were obtained (using TEM) and the critical void volume for failure was measured (using SEM) for each line width. The simulated failure times match the experimental failure times for narrow line widths (1-4μm).

Effect of Line Width on Electromigration of Textured Pure Aluminum Films

1993 ◽  
Vol 309 ◽  
Author(s):  
D.B. Knorr ◽  
K.P. Rodbell
Keyword(s):  
Grain Size ◽  
Line Width ◽  
Pure Aluminum ◽  
Narrow Line ◽  
Dominant Effect ◽  
Aluminum Films ◽  
Narrow Line Width ◽  
Failure Distribution ◽  
Texture Effect ◽  
Line Widths

AbstractThree conditions of pure aluminum films were deposited, patterned into electromigration test structures, and annealed at 400°C for I hour. The grain size distribution was essentially the same for all conditions, but the textures were substantially different. Electromigration failure distributions were developed at 225°C and 1 MA/cm2 for line widths of both 1.8 μm and 0.5 μm. Three conditions were tested at the wider line width while the strongest and weakest textures were evaluated in the narrow line width. Texture exerts a dominant effect at the wider line width where the lines are polycrystalline. The values of t50 increase as texture becomes stronger although σ varies from <0.5 for strong textures to >1 for a bimodal failure distribution in the weakest texture. In the narrow lines, the texture effect is substantially reduced, and the failure distributions are bimodal with a few early fails followed by a monomodal distribution characterized by a low cr. The electromigration behavior is discussed in terms of both texture and the line width to grain size ratio.

A Stress-State Related Void Coalescence Criterion and its Validation

2010 ◽  
Vol 44-47 ◽  
pp. 2656-2660
Author(s):  
Zeng Tao Chen ◽  
Rahul Datta
Keyword(s):  
Stress State ◽  
Volume Fraction ◽  
Cell Model ◽  
Stress Triaxiality ◽  
High Strength Steels ◽  
Void Volume Fraction ◽  
Void Volume ◽  
Void Coalescence ◽  
Element Analysis ◽  
Critical Void

We propose a new critical void volume fraction (fc) criterion that identifies the onset of void coalescence based on the stress state of the material as compared to the definition of the phenomenological criterion by Tvergaard and Needleman [1], where void coalescence is predicted based merely on a constant value for critical void volume fraction. The new fc criterion is obtained using the finite element analysis of the unit cell model of clustered voids. Validation of this new criterion is done by implementing the new coalescence criterion into the Gurson-Tvergaard-Needleman (GTN) [1-3] model and simulating the ductile fracture experiment of a series of angularly notched sheet samples of dual phase (DP), advanced high strength steels (AHSS). A methodology has been devised to construct a stress triaxiality-based void coalescence criterion. Validation of the methodology has been performed using tensile tests of angularly notched samples of DP490 AHSS. Experimental data is compared with FE simulations in order to verify the dependency of void coalescence on stress triaxiality.

Influence of Line-Width on Microstructure and Texture of Damascene Copper Interconnects

2002 ◽  
Vol 721 ◽  
Author(s):  
Kabir J. Mirpuri ◽  
Jerzy A. Szpunar ◽  
Kris J. Kozaczek
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Line Width ◽  
Coincidence Site Lattice ◽  
Orientation Imaging Microscopy ◽  
Copper Interconnects ◽  
Grain Boundary Character Distribution ◽  
Direction Parallel ◽  
Pole Figures ◽  
Line Widths

AbstractThe structure, texture and grain boundary character distribution in the copper interconnects, for ten different line-widths varying from 0.35 to 100 μm, were investigated. Field Emission Gun-SEM orientation imaging microscopy was used in the investigation. The shape of the grains changed with increasing line-widths. The frequency of occurrence of more than one grain along the width and grain size increased with increasing line-width. The mean grain size was found to be 0.2 μm in the smallest lines with width 0.35 μm and as high as 2.5 μm in the 100 μm lines which were the largest in width. The grain size distribution was skew-symmetric with an inclination towards smaller size. The (111) pole figures, inverse pole figures and the area fraction of the grain boundaries with different misorientation angles were computed for all the line-widths. The 0.4 and 0.5 μm lines had stronger {111} component in the direction transverse to the trenches. The intensity of the component increased with decreasing width. The 0.35 μm lines, which were narrowest in width had two {111} components with <110> direction parallel to transverse and longitudinal directions. The higher line-widths had predominantly (111) fiber texture though presence of {111}<110> could also be identified. Number fraction of the grain boundaries with misorientation angle between 55-62° was maximum in all line-widths. The ∑3 and ∑9 coincidence site lattice (CSL) boundaries were present in significant number in all the investigated lines. Presence of twins running along the width could be easily identified in the submicron lines.

Narrow line-width resonant cavity enhanced photodetectors operating at 1.55μm

2008 ◽  
Vol 281 (6) ◽  
pp. 1582-1587 ◽  
Author(s):  
R.W. Mao ◽  
C.S. Tsai ◽  
J.Z. Yu ◽  
Q.M. Wang
Keyword(s):  
Line Width ◽  
Resonant Cavity ◽  
Narrow Line ◽  
Narrow Line Width

scholarly journals Influence of Steel Grain Size on Residual Stress in Grinding Processing

2010 ◽  
Vol 638-642 ◽  
pp. 2389-2394 ◽  
Author(s):  
Masahide Gotoh ◽  
Katsuhiro Seki ◽  
M. Shozu ◽  
Hajime Hirose ◽  
Toshihiko Sasaki
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Stress State ◽  
Mechanical Grinding ◽  
Fine Grained ◽  
Residual Stress State ◽  
Analysis Methods ◽  
Average Grain Size ◽  
Fine Grained Steels

The fine-grained rolling steels NFG600 and the conventional usual rolling steels SM490 were processed by sand paper polishing and mechanical grinding to compare the residual stress generated after processing. The average grain size of NFG600 and SM490 is 3 μm and 15μm respectively. Therefore improvement of mechanical properties for such fine-grained steels is expected, it is important to understand the residual stress state of new fine-grained materials with processing. In this study, multi axial stresses of two kinds of specimens after polishing and grinding were measured by three kinds of analysis methods including cos-ψ method. As a result, as for σ33, the stress of NFG was compression, though that of SM490 was tension.

Process-Oriented Stress Modeling and Stress Evolution During Cu/Low-K BEOL Processing

2004 ◽  
Vol 812 ◽  
Author(s):  
Charlie Jun Zhai ◽  
Paul R. Besser ◽  
Frank Feustel
Keyword(s):  
Stress State ◽  
Mechanical Stress ◽  
Plane Stress ◽  
Cmos Technology ◽  
Film Deposition ◽  
Stress Evolution ◽  
Process Step ◽  
Dual Damascene ◽  
Process Oriented ◽  
Low K

AbstractThe damascene fabrication method and the introduction of low-K dielectrics present a host of reliability challenges to Cu interconnects and fundamentally change the mechanical stress state of Cu lines. In order to capture the effect of individual process steps on the stress evolution in the BEoL (Back End of Line), a process-oriented finite element modeling (FEM) approach was developed. In this model, the complete stress history at any step of BEoL can be simulated as a dual damascene Cu structure is fabricated. The inputs to the model include the temperature profile during each process step and materials constants. The modeling results are verified in two ways: through wafer-curvature measurement during multiple film deposition processes and with X-Ray diffraction to measure the mechanical stress state of the Cu interconnect lines fabricated using 0.13um CMOS technology. The Cu line stress evolution is simulated during the process of multi-step processing for a dual damascene Cu/low-K structure. It is shown that the in-plane stress of Cu lines is nearly independent of subsequent processes, while the out-of-plane stress increases considerably with the subsequent process steps.

A tunable narrow-line-width multi-wavelength Er-doped fiber laser based on a high birefringence fiber ring mirror and an auto-tracking filter

2008 ◽  
Vol 281 (1) ◽  
pp. 90-93 ◽  
Author(s):  
Xiu-jie Jia ◽  
Yan-ge Liu ◽  
Li-bin Si ◽  
Zhan-cheng Guo ◽  
Sheng-gui Fu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Line Width ◽  
Narrow Line ◽  
Fiber Ring ◽  
High Birefringence ◽  
Narrow Line Width ◽  
Multi Wavelength ◽  
Tracking Filter ◽  
Er Doped

A Stable Narrow Line-Width Dual-Wavelength Fiber Laser Based on Nonlinear Polarization Rotation with a High Finesse Ring Filter

2011 ◽  
Vol 130-134 ◽  
pp. 1876-1879
Author(s):  
Xiu Feng Yang ◽  
Lei Peng ◽  
Zheng Rong Tong ◽  
Ye Cao ◽  
Feng Juan Dong
Keyword(s):  
Fiber Laser ◽  
Line Width ◽  
Extinction Ratio ◽  
Dual Wavelength ◽  
Narrow Line ◽  
Polarization Rotation ◽  
Nonlinear Polarization ◽  
Narrow Line Width ◽  
Nonlinear Polarization Rotation ◽  
High Finesse

A stable narrow line-width dual-wavelength fiber laser based on nonlinear polarization rotation with a high finesse ring filter is proposed and demonstrated. A polarization-dependent-isolator (PDI) and a section of polarization maintaining fiber (PMF) form an equivalent birefringent filter. Moreover, a ring filter can produce high finesse due to the weak gain generated by the EDF. As a result, two stable wavelengths are generated which both have about 18dB extinction ratio, 16dB side mode suppression ratio (SMSR) and 0.16nm 3dB line-width. Plus, less than 2 pm of the wavelengths shift and smaller than 0.4 dB of the optical power fluctuation when the system is operating in room environment for a period of 40 minutes indicate that the ultra narrow line-width fiber laser is very stable.

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