Experimental and numerical investigations on Cu/low-k interconnect reliability during copper pillar shear test

2015 ◽  
Author(s):  
Clement Sart ◽  
Sebastien Gallois-Garreignot ◽  
Vincent Fiori ◽  
Olivier Kermarrec ◽  
Caroline Moutin ◽  
...  
Keyword(s):  
Shear Test ◽  
Numerical Investigations ◽  
Interconnect Reliability ◽  
Low K

Reliability Assessment and Failure Analysis of G-Helix, a Free-Standing Compliant Off-Chip Interconnect

2009 ◽  
Vol 6 (1) ◽  
pp. 59-65
Author(s):  
Karan Kacker ◽  
Suresh K. Sitaraman
Keyword(s):  
Failure Analysis ◽  
Dielectric Material ◽  
Organic Substrate ◽  
Wafer Level ◽  
Free Standing ◽  
Fine Pitch ◽  
Cross Section Area ◽  
Interconnect Reliability ◽  
Compliant Interconnect ◽  
Low K

Continued miniaturization in the microelectronics industry calls for chip-to-substrate off-chip interconnects that have 100 μm pitch or less for area-array format. Such fine-pitch interconnects will have a shorter standoff height and a smaller cross-section area, and thus could fail through thermo-mechanical fatigue prematurely. Also, as the industry transitions to porous low-K dielectric/Cu interconnect structures, it is important to ensure that the stresses induced by the off-chip interconnects and the package configuration do not crack or delaminate the low-K dielectric material. Compliant free-standing structures used as off-chip interconnects are a potential solution to address these reliability concerns. In our previous work we have proposed G-Helix interconnects, a lithography-based electroplated compliant off-chip interconnect that can be fabricated at the wafer level. In this paper we develop an assembly process for G-Helix interconnects at a 100 μm pitch, identifying the critical factors that impact the assembly yield of such free-standing compliant interconnect. Reliability data are presented for a 20 mm × 20 mm chip with G-Helix interconnects at a 100 μm pitch assembled on an organic substrate and subjected to accelerated thermal cycling. Subsequent failure analysis of the assembly is performed and limited correlation is shown with failure location predicted by finite elements models.

Qualification of bumping processes: Experimental and numerical investigations on mechanical stress and failure modes induced by shear test

2015 ◽  
Vol 55 (6) ◽  
pp. 980-989 ◽  
Author(s):  
Sébastien Gallois-Garreignot ◽  
Naceur Benzima ◽  
Etienne Benmussa ◽  
Caroline Moutin ◽  
Pierre-Olivier Bouchard ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Shear Test ◽  
Failure Modes ◽  
Numerical Investigations

Assess low-k/ultralow-k materials integrity by shear test on bumps of a chip

2018 ◽  
Vol 29 (19) ◽  
pp. 16416-16425 ◽  
Author(s):  
Chen Yang ◽  
Lei Wang ◽  
Kehang Yu ◽  
Jun Wang ◽  
Fei Xiao ◽  
...  
Keyword(s):  
Shear Test ◽  
Low K

Localization of Cu/Low-k Interconnect Reliability Defects by Pulsed Laser Induced Technique

2007 ◽  
Author(s):  
T.L. Tan ◽  
A.C.T. Quah ◽  
C.L. Gan ◽  
J.C.H. Phang ◽  
C.M. Chua ◽  
...  
Keyword(s):  
Pulsed Laser ◽  
Interconnect Reliability ◽  
Low K

Abstract In this paper, the application of pulsed-TIVA for the localization of Cu/low-k interconnect reliability defects in comb test structures is described. Two types of subtle dielectric defects which are otherwise not detectable with conventional TIVA can be detected with pulsed-TIVA.

scholarly journals Numerical Analysis of Impact Loading of Adhesive Joints

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Andrzej Komorek ◽  
Jan Godzimirski ◽  
Agata Pietras
Keyword(s):  
Impact Strength ◽  
Shear Test ◽  
Adhesive Joints ◽  
Normal Stresses ◽  
Principal Stresses ◽  
Numerical Investigations ◽  
Block Shear ◽  
Bonded Joint ◽  
Numerical Research ◽  
Strength Of Adhesive Joints

Due to small repeatability of results of impact strength of adhesive joints, particularly those performed on different test machines, the authors were inspired to conduct experimental and numerical research in this field. The investigation used the Block Shear Test. The authors compared impact strength of samples which were loaded in a normative and nonnormative manner and also the dependence in impact strength with regard to the distance between the impactor’s edge and the surface of the bonded joint. The numerical calculations were carried out in the program Ansys, using the Explicit Dynamics module. The authors proposed a way of modelling the impactor of the pendulum hammer. It was found that a change in the direction of applying the load to the sample and rotating the loaded sample piece in relation to the edge of the impactor results in a significant change in the Max Principal Stresses. Numerical investigations show that lower values of Max Principal Stresses occur in joints which are characterized by larger impact strength, determined experimentally. It was also noted that moving away the edge of the impactor from the surface of the adhesive joint increases normal stresses perpendicular to the surface of the joint.

Study on BEOL Failures in a Chip by Shear Tests of Copper Pillar Bumps

2019 ◽  
Vol 141 (1) ◽  
Author(s):  
Lei Wang ◽  
Jun Wang ◽  
Fei Xiao
Keyword(s):  
Shear Test ◽  
Focused Ion Beam ◽  
Failure Modes ◽  
Ion Beam ◽  
Maximum Shear Stress ◽  
Dielectric Materials ◽  
Electrical Performance ◽  
Element Analysis ◽  
Shear Speed ◽  
Low K

A chip with 40 nm technology node and beyond generally incorporates low-k/ultra-low-k (LK/ULK) dielectric materials and copper traces in the back end of line (BEOL) to improve its electrical performance. Owing to the fragile low-k/ultra-low-k materials, the BEOL becomes vulnerable to external loads. When a copper pillar bump (CPB) above the BEOL sustains a shear force due to thermal mismatch between the components, failures occur in the microstructures of BEOL, especially in low-k materials. We fabricated CPBs on the chips and investigated fractures in the BEOL by a shear test approach. The shear speed and shear height are varied to examine their effects. The tested samples were analyzed via focused ion beam (FIB) and scanning electron microscope (SEM) to reveal the microstructures degradation or breaks in the BEOL, and they are classified into three kinds of failure modes. Assisted by a finite element analysis (FEA), the failure mechanism was explained and associated with the failure modes. The studies showed that the shear speed has a little influence on the maximum shear stress, but the increase of shear height leads to more fractures in the low-k materials. It indicated that decreasing the height of CPBs is helpful for reducing destruction risk of the BEOL under the thermomechanical loads. Based on a parametric study for shearing test simulation of a single CPB, the modulus and thickness of polyimide (PI) were found a larger impact on the stresses in the low-k material layer, but the modulus of low-k materials has a smaller effect on the stress. Generally, the shear test of a CPB can help to evaluate the integrity of BEOL in a chip.

Impact of Fabrication Process, Layout Variation and Packaging Process on Cu/Low-k Interconnect Reliability

2007 ◽  
Vol 990 ◽  
Author(s):  
Aditya Karmarkar ◽  
Xiaopeng Xu ◽  
Dipu Pramanik ◽  
Xi-Wei Lin ◽  
Greg Rollins ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Fabrication Process ◽  
Stress Distributions ◽  
Packaging Process ◽  
Integration Density ◽  
Final Stress ◽  
Interconnect Reliability ◽  
Multi Level ◽  
Areas Of Concern ◽  
Low K

ABSTRACTThe industry trend towards smaller feature size and higher integration density leads to multi-level Cu/low-k interconnect schemes with reduced line width and spacing. Mechanical stress is generated during interconnect fabrication. The spatial distribution of the stress is strongly affected by the layout variation. The packaging process generates a global chip level stress that permeates to the local interconnect level. Stress related failures and yield loss are major areas of concern for Cu/low-k interconnects. The effects of fabrication process, layout variation, and packaging process on the final stress distributions in Cu/low-k interconnect structures are examined and the reliability impact of mechanical stress is assessed.

Numerical Analysis of Packaging-Induced Failures in Cu/Low-k Interconnects

2008 ◽  
Vol 1079 ◽  
Author(s):  
Aditya Pradeep Karmarkar ◽  
Xiaopeng Xu ◽  
Xiao Lin ◽  
Greg Rollins ◽  
Victor Moroz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Stresses ◽  
Copper Interconnects ◽  
Circuit Performance ◽  
Packaging Process ◽  
Interconnect Reliability ◽  
Multi Level ◽  
The Impact ◽  
Low K ◽  
Package Reliability

ABSTRACTWith decreasing feature sizes for every technology node, multi-level metallization schemes that employ copper interconnects and low-k dielectrics are required to achieve the requisite circuit performance. Here, the effects of the mechanical stresses originating from the packaging process on Cu/Low-k interconnects are assessed. The impact of package defects on interconnect reliability is also analyzed. It is seen that the package reliability varies with underfill mechanical properties. The packaging process introduces global level stresses that propagate to the local, i.e. interconnect, level. Moreover, the package defects also have an adverse impact on the mechanical stresses in the metallization structure. The package defects alter the mechanical stresses in the metal lines and affect the reliability. The complex interaction between packaging process induced stresses, package level defects and mechanical properties of various materials is analyzed in order to create robust interconnect designs.

Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

1976 ◽  
Vol 34 ◽  
pp. 334-335 ◽  
Author(s):  
Avril V. Somlyo ◽  
H. Shuman ◽  
A.P. Somlyo
Keyword(s):  
Smooth Muscle ◽  
Electron Probe ◽  
Preliminary Report ◽  
Cell Damage ◽  
Electron Probe Analysis ◽  
Perinuclear Space ◽  
Probe Analysis ◽  
High K ◽  
Low K ◽  
Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

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