Finite Element Calculations of Strains in Passivated Metal Lines

1997 ◽  
Vol 473 ◽  
Author(s):  
I. Eppler ◽  
H. Schroeder ◽  
W. Schilling
Keyword(s):  
Finite Element ◽  
Integrated Circuits ◽  
Elastic Constants ◽  
Mean Values ◽  
Thermally Induced ◽  
Thermal Expansion Coefficients ◽  
Parallel Lines ◽  
Finite Element Calculations ◽  
Infinite Array ◽  
Passivated Metal

ABSTRACTPassivated metal lines, commonly used in integrated circuits, show thermally induced strains and stresses due to the mismatch of the thermal expansion coefficients of the lines and their surroundings. These strains depend on the geometry and the elastic constants of both, line and surroundings (i.e. substrate and passivation) and - for the case of an array of parallel lines - on the repetition distance of the lines. For a given set of these parameters the strains and stresses can be obtained from finite element calculations using a model with plane strain conditions.In order to obtain the dependences of the strains from these parameters systematic finite element calculations have been made for an infinite array of parallel lines with variations of the geometries and the elastic constants.Since only the volume mean values of the metal strains can be measured easily (X-ray, wafer curvature method (metal stress)), the dependences of these mean values on the different parameters are presented.

Analysis of Stresses and Strains In Passivated Metal Lines

1996 ◽  
Vol 436 ◽  
Author(s):  
I. Eppler ◽  
H. Schroeder ◽  
U. Burges ◽  
W. Schilling
Keyword(s):  
Integrated Circuits ◽  
Shear Deformation ◽  
Plastic Shear ◽  
Thermally Induced ◽  
Flat Substrate ◽  
Thermal Expansion Coefficients ◽  
Aspect Ratios ◽  
Induced Stresses ◽  
Proper Values ◽  
Passivated Metal

AbstractPassivated metal lines, commonly used in integrated circuits, show thermally induced stresses due to the difference of the thermal expansion coefficients of the lines and their surroundings. These stresses cause voidage and plastic flow of the lines. Aim of the analysis was to derive equations connecting experimentally measured strains or stresses by the X-ray diffraction and wafer curvature techniques with the magnitude of voidage and plastic shear deformation of the lines.Using the concepts of linear elasticity the volume averaged stresses of an array of parallel interconnects embedded in a passivation layer on a flat substrate are analysed. Equations are derived connecting the volume averaged stresses in the metal and in the passivation with the “Heigen-strains” of the metal which characterize the true (stress free) thermal strains and plastic deformation strains of the metal. The coefficients entering these equations are determined from (elastic) finite element method (FEM) calculations performed for various geometries and aspect ratios of the metal lines. Choosing the proper values of the coefficients allows the eigen- strains to be determined from the experimental data.By comparison of the evaluated eigen-strains with the purely elastic eigen-strains ΔαΔT the extent of voidage and/or plastic shear deformation of passivated metal lines caused by thermally induced stresses can be determined model independently.

Analysis Of Stresses And Strains In Passivated Metal Lines

1996 ◽  
Vol 428 ◽  
Author(s):  
I. Eppler ◽  
H. Schroeder ◽  
U. Burges ◽  
W. Schilling
Keyword(s):  
Integrated Circuits ◽  
Shear Deformation ◽  
Plastic Shear ◽  
Thermally Induced ◽  
Flat Substrate ◽  
Thermal Expansion Coefficients ◽  
Aspect Ratios ◽  
Induced Stresses ◽  
Proper Values ◽  
Passivated Metal

AbstractPassivated metal lines, commonly used in integrated circuits, show thermally induced stresses due to the difference of the thermal expansion coefficients of the lines and their surroundings. These stresses cause voidage and plastic flow of the lines. Aim of the analysis was to derive equations connecting experimentally measured strains or stresses by the X-ray diffraction and wafer curvature techniques with the magnitude of voidage and plastic shear deformation of the lines.Using the concepts of linear elasticity the volume averaged stresses of an array of parallel interconnects embedded in a passivation layer on a flat substrate are analysed. Equations are derived connecting the volume averaged stresses in the metal and in the passivation with the “eigen-strains” of the metal which characterize the true (stress free) thermal strains and plastic deformation strains of the metal. The coefficients entering these equations are determined from (elastic) finite element method (FEM) calculations performed for various geometries and aspect ratios of the metal lines. Choosing the proper values of the coefficients allows the eigen- strains to be determined from the experimental data.By comparison of the evaluated eigen-strains with the purely elastic eigen-strains ΔaΔT the extent of voidage and/or plastic shear deformation of passivated metal lines caused by thermally induced stresses can be determined model independently.

Detection and Characterization of an Electrical Failure Induced during Laser Ablation of Packages

2008 ◽  
Author(s):  
P. Schwindenhammer ◽  
H. Murray ◽  
P. Descamps ◽  
P. Poirier
Keyword(s):  
Laser Ablation ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Ablation Process ◽  
Thermally Induced ◽  
Electrical Failure ◽  
Electrical Phenomenon ◽  
Semiconductor Packages ◽  
Complex Semiconductor

Abstract Decapsulation of complex semiconductor packages for failure analysis is enhanced by laser ablation. If lasers are potentially dangerous for Integrated Circuits (IC) surface they also generate a thermal elevation of the package during the ablation process. During measurement of this temperature it was observed another and unexpected electrical phenomenon in the IC induced by laser. It is demonstrated that this new phenomenon is not thermally induced and occurs under certain ablation conditions.

Thermally Induced Delamination Buckling of a Thin Metal Layer on a Ceramic Substrate

2003 ◽  
Vol 125 (4) ◽  
pp. 512-519 ◽  
Author(s):  
C. J. Liu ◽  
L. J. Ernst ◽  
G. Wisse ◽  
G. Q. Zhang ◽  
M. Vervoort
Keyword(s):  
Failure Modes ◽  
Research Effort ◽  
Metal Layer ◽  
Electronic Packages ◽  
Ceramic Substrates ◽  
Thermally Induced ◽  
Thermal Expansion Coefficients ◽  
Interface Delamination ◽  
Delamination Buckling ◽  
Expansion Coefficients

Interface delamination failure caused by thermomechanical loading and mismatch of thermal expansion coefficients and other material properties is one of the important failure modes occurring in electronic packages, thus a threat for package reliability. To solve this problem, both academic institutions and industry have been spending tremendous research effort in order to understand the inherent failure mechanisms and to develop advanced and reliable experimental and simulation methodologies, thus to be able to predict and to avoid interface delamination before physical prototyping. Various damage mechanisms can be involved and can result in interface delamination phenomena. These are not all sufficiently addressed and/or reported so far, probably because of the complexities caused by the occurrence of strong geometric and materials nonlinearities. One of the phenomena being insufficiently understood so far is the so-called buckling-driven delamination of thin metalic layers on ceramic substrates. This phenomenon will be discussed in the present paper.

Research on Thermally Induced Deformation of Reinforcing Plate Based on Finite Element Simulation

2012 ◽  
Vol 197 ◽  
pp. 139-143
Author(s):  
Hua Bai ◽  
Yi Du Zhang
Keyword(s):  
Finite Element ◽  
Ambient Temperature ◽  
Finite Element Simulation ◽  
Temperature Change ◽  
Large Scale ◽  
Machining Process ◽  
Reinforcement Structure ◽  
Thermally Induced ◽  
Finite Element Software ◽  
Element Simulation

The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.

Investigated Effect of Points Charge of the Receptors on the Conduction of Semiconductor Nanowire

2015 ◽  
Vol 1109 ◽  
pp. 167-170
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Mijanur Rahman ◽  
Tijjani Adam ◽  
A.H. Azman ◽  
...  
Keyword(s):  
Finite Element ◽  
Oxide Layer ◽  
Point Charge ◽  
Potential Distribution ◽  
Silicon Nanowire ◽  
Comsol Multiphysics ◽  
Functional Layer ◽  
Semiconductor Nanowire ◽  
Finite Element Calculations

The paper reported a study on an effect of the point charge of the bio-interface of a nanowire field biosensor on the conductance of the nanowire, through finite element calculations using COMSOL Multiphysics. A model with 5 layers starting with silicon nanowire of radius 10nm surrounded by a 2-nm oxide layer, and the oxide layer were surrounded by a 5 nm thick functional layer and 2 points charge were considered for this study and last layer is for electrolyte. The results shows that is different voltages with points change is that effected on the conductance of nanowire that is clear from different of potential distribution of point charge.

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