Design for reliability of BEoL and 3-D TSV structures – A ... - Sematech

March 17, 2011 • Santa Clara, California
Design for reliability of BEoL and 3‐D TSV structures –A joint
effort of FEA and innovative experimental techniques
Jürgen Auersperg 1 , D. Vogel 1 , M.U. Lehr 3 , M. Grillberger 3 , J. Oswald 3 ,
S. Rzepka 1 , B. Michel 1,2
1
Fraunhofer Institute for Electronic Nano Systems ENAS, Germany
2
Micro Materials Center at Fraunhofer Institute for Reliability bl and Microintegration IZM, Germany
4
GLOBALFOUNDRIES Dresden Module One LLC & Co. KG, Dresden, Germany
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Outline
• Motivation
• Multi‐level FE modeling of CPI
• Multi‐failure evaluation for
Near‐Chip‐Edge and Near‐Bump Cracks in BEoL
• Role of Initial Stresses
• TSV –damage and delamination investigation
• Required experiments
• Summary and Outlook
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Task – Heterogeneous Integration ‐ Packaging
Bridging the gap between chip and application
Bump side

Multiscale –why?
Geometry
Packaged microprocessor
(eight symmetric model
Packaged microprocessor
(10 –40 mm size)
BEoL stack region
Ni layer
PI layer
Bump side
HMT solder
Underfill
BEoL‐stack
(5 –10 µm size)
Feature sizes:
some nm!
Transistor side

Multiscale –why?
Geometry
Bridge 40 mm to sub‐nm for
Chip Packaging Interaction investigations of
a BEoL structure
Structural details: sub ‐ nm
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multiscale –why?
Structure
Nano lawn for
interconnect
formation
Can these materials longer be
modeled as homogeneous
materials?
Atomistic level modeling
Molecular dynamics
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Low‐k dielectrics (nano‐porous)
Polymer: 23 H2O for 98 °C/ 100 RH
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multiscale ‐ Molecular Dynamics –Two Ways used
Structure
The way I:
1. Modeling of the molecular structure
2. Homogenization in a unit cell
3. Use it directly inside a Macro‐model,
a FE‐Model for instance
The way II:
1. Modeling of the molecular structure
2. Simulations towards extraction of key‐
properties Finite (YOUNG’s Element modulus, Region CTE,
diffusion coefficients)
Crack Tip Molecular
3. Use these properties Dynamics Region inside a Macrodla
FE‐Model lfor instance
model, Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Polymer: 23 H2O for 98 °C/ 100 RH
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Moisture Diffusion in Epoxy by Molecular Dynamics
Motivation:
i
Understand diffusion phenomena as structureproperty
correlation for reliability prediction
Structure
Method
Materials: Epoxy with sev. chem. composition
Exp: measure diffusion D & saturation S
Sim: molecular dynamics
Result:
D and S are strong functions of (as tested)
‐ density,
‐ polarity,
‐ chain length,
‐ stoichiometry,
‐ temperature
Sim & Exp show correct tendencies
Quantitative Results need correct
3D network representation of epoxy resins
Jürgen Auersperg, D. Vogel, M.U. Lehr,
E.D. M. Dermitzaki, Grillberger, J. Bauer, J. Oswald, B. Wunderle, S. Rzepka, B. B. Michel Michel
m^2/s) oeff.
Diff D co (cm
2.50E-007
2.00E-007
1.50E-007
1.00E-007
5.00E-008
0.00E+00000E 000
Polymer: 23 H2O for 98 °C/ 100 RH
Varied parameters = Arrow:
increasing polarity and chain lenght
Exp
Experiment:98°C/100RH
Diff co oeff.
2/s)
D (cm^
3.0x10 -6
2.5x10 -6
2.0x10 -6
1.5x10 -6
1.0x10 -6
5.0x10 -7
00 0.0
98 °C/ 100 rh
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka
Sim
Molecular Dynamics 98°C/100RH

Multiscale – Finite Element Techniques ‐ Substructuring
Continuum
Multi‐level
Substructuring
256x
3
4
2
1
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multiscale – Finite Element Techniques – Submodeling
Continuum
Multi‐level
Submodeling
256x
2
1
3
4
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multi‐failure Evaluation
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

2 nd Failure‐Mode – Risk for Die‐Cracking, Cracking of Substrates, …
Smooth bending
w/o singularities in
Stress field with
well known stress
stresses/strains singularity 1 r
Stress field with
stress singularity
1
r
Well known angle from
anisotropic etching, for instance
Classical l strength thhypotheses
Generalized stress intensity
it Fracture mechanics:
max. surface stress evaluation factor (gSIF) A‐factor …
K‐factor (SIF), J‐integral, energy
Weibull‐plots
release rate (ERR) …
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3 rd Failure‐Mode – Delamination at Materials Interfaces
20µm
(
i
) 0
xx
yy
K r
i
/
2
r
Hutchinson et al.
1992
r
0
2a
exp
2
for
yy
and
r
*
0
a
2 exp
for
xy
Mixed Mode Situation
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Cohesive Zone Modeling –Drawbacks and Challenges
CZM
DCB specimen with crack propagation under continuous
displacement controlled opening
! CZM‐Models have to handle and
deliver damage parameters
(damage progress per
cycle/time)
CZM with damage options
Subjects of current research!
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

XFEM ‐ Mesh Independent Crack Propagation
XFEM
FEM shape functions
FEM unknowns
Discontinuous
enrichment functions
XFEM unknowns
FEM
displacement
all nodes
Crack crossing an element
XFEM
Heaviside enrichment
subset of nodes
Crack tip in an element
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

BEoL Stack of an IC – Cracking/Delamination ‐ Locations and Impacts
Near-chip-edge cracks under Chip Package Interaction (CPI)
Crack stop structure
Near-bump cracking during reflow
(NBC)
Leadfree
Copper Pillars
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Chip Package Interaction (CPI)
Near-chip-edge cracks
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

BEoL Stack of an IC –Near‐Bump‐Cracks –Region of Interest
NBC
Packaged FE‐model
(eight symmetric model)
LID adhesive
BEoL stack region
Ni layer
PI layer
TIM1
Die
Underfill
Soldermask
HMT solder
Underfill
Board
gap
LJT solder
Soldermask
Boardpad
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3D BEoL Stack Part‐model – Submodeling with Substructures
NBC
Substructure
Finite elelement
characteristic size in
BEoL‐stack
< nm
Substructure region
Replacement of the finest (1x) structures
by superelements (repeatedly used) leads
to a dramatically reduced model size
(by factor 3),
complete model
(with and without element edges)
vias and
metal traces
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3d Local Model of a BEoL Part –Crack Introduced ‐ SubModeling
NBC
Global model
Submodel
Initial crack
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3d Local Model of a BEoL Part – SubModel Placing and Orientation
NBC
Submodel driving nodes
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multiscale –Substructure & Submodeling of a BEoL stack of an IC
NBC
Mode II
(In‐Plane Shear)
Mode III
(Out‐of‐Plane Shear)
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Multiscale –Substructure & Submodeling of a BEoL stack of an IC
NBC
Crack kdii driving force along the crack front
Results:
• Find most critical places with
• Material interface delamination
and/or
• Cohesive fracture of material
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

BEoL Stack of an IC –Die Edge Cracking ‐ Interface Fracture Mechanics
CPI
1,40
max. norm. ERR vs Crack Length
orm. G
n
1,20
1,00
0,80
060
0,60
Chip corner
0,40
margin 51 µm to crack-stop-structure
0,20
0,00
margin 51 µm to crack-stop-structure
w/o crack-stop-structure
structure
0 20 40 60 80 100 120
crack length [µm]
Crack stop structure
t
Margin
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

BEoL Stack of an IC –Die Edge Cracking ‐ Interface Fracture Mechanics
CPI
• 10 bimaterial interface paths +
• 4 cohesive crack paths in ULK
3
Max. ERR in diff. Crack Paths, 40 µm Crack Length marg 100
2,9
2,8
ge
en. G
2,7
2,6
Chip corner
2,5
Path
24
2,4
Crack stop structure
t
2,3
1 2 3 4 5 6 7 8 9 path
10
Margin
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

NBC
Reflow Process Dependent
Near‐Bump‐Cracks in BEoL
Leadfree
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3d Global‐Local Model Simulations –Stress States
NBC
Peeling Stresses at 0 °C (under CPI)
Peeling Stresses at RT (end of reflow)
Chip center
Chip center
Chip center
Avoid worst case: white spots in SAM
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Cooling Down from Soldering –Reflow Profiles
NBC
Highlead
Leadfree
Aggressive cooling
slope
Some studies have shown
that an aggressive cooling
slope can provide optimal
diffusion of material and
fine eutectic grain
structures
Mohanty, R., Apell, M. C., Burke,
R.: Reflow Process Control
Monitoring, and Data Logging,
URL:
http://www.emsnow.com/cnt/fil
es/White%20Papers/speedReflo
wProcessControl.pdf
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

FE‐Modeling of the Soldering Process –Reflow Profile Modification
NBC
• Highest G for Leadfree Soldering
• Stress relaxation of the solder joints
Temperature vs. Time
300
Leadfree profile
250
Leadfree profile 02
Highlead profile
200 Highled profile 02
Highled profile 03
150
100
50
0
0 400 800 1200 1600 2000
Cooling down
period discussed
here
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Crack and Damage Initiation/Propagation Investigation
NBC
Damage
Problems:
Material/Interface properties
Integration Stability/Controlability
Damage propagation investigation in order
to find highest damage risk locations
XFEM
XFEM in order to find crack starting locations
and paths
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Chip Package Interaction and Initial Stresses
From Manufacturing Processes
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Local Residual Stress Measurement ‐ Approaches ‐
Electron Back Scattered Diffraction
(EBSD) based method
• deformation of Kikuchi diffraction pattern
as measure of stress
• determines stress tensor comp.
Residual
Stresses
Stress Release Technique (fibDAC)
utilizing deformation field after trench
milling by FIB
Raman Spectroscopy
• uses shift of Raman
bands due to stress
• TERS effect with
potential to obtain
resolution beyond 100
nm
D. Jürgen Vogel, A. Auersperg, Gollhardt
D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Local stress measurement concept –stress relief by FIB milling (fibDAC)
Material removal
by
FIB feature milling
Stress relief, i.e.
deformation
nearby milling pattern
Solution of the
Quantifying
mechanical stress relief
Displacement
df deformation field problem by
field fitting
by
Digital Image
Finite Element Analysis
Correlation (DIC)
(FEA)
Stress values
D. Jürgen Vogel, A. Auersperg, Gollhardt
D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Near‐Bump Cracks in BEoL – Taking Initial Stresses into Account
Crack Paths 6 and 14 with ULK vs. Gen3
During whole processing w/o and
with initial stresses
1,2
1
max. ERR for all Steps at the Crack Front
With initial stresses
1,00000
G
0,8
0,66285
gen.
0,6
0,44671 0,43292
0,4
0,2
0,22349
0,12081
0,18113
0,10560
0
Path 6
Path 6
Path 14
Path 14
Path 6
Path 6
Path 14
Path 14
ULK Gen3 ULK Gen3 ULK is Gen3 is ULK is Gen3 is
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

3D‐Integration ti – TSV and BEoL
Cracking/Delamination risks during BEoL‐manufacturing on top of TSVs?
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV and BEoL‐structure
Protrusion
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV and BEoL‐structure ‐ Possible Failure Mode – Delamination
Protrusion
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV and BEoL‐structure ‐ Possible Failure Mode – Delamination
Protrusion
Assumtions:
• Initial delamination between TSV and barrier
• Initial stresses in TSV and introduced step by step
during BEoL‐processing
• Partly delaminated BEoL
• Cracks in BEoL
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV and BEoL‐structure – Delamination Investigation
Changing stress
traction direction
Strong dependence on
stress free assumptions
Crack flanks partly in
contact – negative Jint
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Sequential Build Up –Cohesive Zone Modeling – BEoL to MOL Delamination
Cohesive zone elements introduced between MOL and BEoL – damaging during
thermal loading delamination of initially undamaged material interface
d
Measure for interface
loading (BEoL removed for
better demonstration
Interface totally damaged at
distance ‘d’
TSV
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Silicon
‣ Define CZM‐properties:
Tn, Ts, Tt, GI, GII, GIII, En,
Es, Et (all are estimated
here!)
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

and BEoL‐structure ‐ Possible Failure Mode – Damaging of Copper
‣ Define damage ‐
properties:
pl , ‐p/q, rate , G c , …)all
are estimated here!)
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Material lProperty Dt Determination
ti
Size Dependent Material Behavior
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Material Behavior ‐ Measure Required Properties
Dynamical‐Mechanical Analysis (DMA) Thermomechanical Analysis (TMA) Creep data eval. (Solder)
Temp.dep. creep data (Epoxy) Stress relaxation data (Epoxy) Poisson’s s ratio eval.
Jürgen Auersperg, D. Vogel, M.U. Lehr,
H. Walter, M. Grillberger, J. Auersperg J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Nanoindentation in low‐K Dielectrics
Bump side
Thin layers
BEoL stack
7 µm
F, u
Intenter
Thin Layer
Substrate
t
For TSV:
• Initial yield stress
• Hardening ade gbehavior
N]
Force [µ
1400
1200
1000
800
600
400
200
Chip side
Sim
Measurement
Experiment
E=145, sy=1600-10000
0
0 20 40 60 80
-200
Distance [nm]
Experiment Simulation Agreement
Parameter – extraction only possible by coupled Sim & Exp
Raul Jürgen
Mrosko, Auersperg,
Saskia Huber, D. Vogel,
O. Wittler
M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV Copper –YOUNGs Modulus by nano‐Indentation
P13 Messung 3
P13 Messung 3
46,405
demo demo demo demo demo
140
120
Y(mm)
46,400
demo demo demo demo demo
demo demo demo demo demo
demo demo demo demo demo
Er(GPa)
100
80
60
46,395
demo demo demo demo demo
40
-82,275 275 -82,270 270 -82,265 265 -82,260
260
X(mm)
demo demo demo demo demo
46,390
-82,275 -82,270 -82,265 -82,260
X(mm)
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Copper Material Behavior– Properties Necessary
Necessary to know:
• Young's‐modulus dep. On Temperature
• Initial yield stress
• Hardening vs. plastic strains
• Regarding TSV: initial stress state
Xi Liu, Qiao Chen, Pradeep Dixit, Ritwik Chatterjee, Rao R.
Tummala, and Suresh K. Sitaraman, Failure Mechanisms and
Optimum Design for Electroplated Copper Through‐Silicon Vias
(TSV), 2009 Electronic Components and Technology
Conference, pp. 624 ‐ 629
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Size Effects and Damage in Thin Metallic Films during Nano‐Indentation
Meso‐mechanics
Homogeneous
• Strain gradient plasticity
• Higher order stress theories
Dislocation movement
restrictions inside boundaries
D. Gross, A. Trondl:
Numerical Simulation of Size Effects and
Damage in Thin Metallic Films during Nano‐
Indentation,
Proc. ICF 12, Ottawa, CA, 2009, Paper on CD:
fin00457.pdf
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Damage and Fracture Toughness Characterization
ti
Size Dependent Material Behavior
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Interface Fracture Toughness Tests
P
Pull‐off test schematic of substrate,
interface and pull stud
Modified CT‐specimen
Peel test
Pull‐out test Brazilian disk specimen Superlayer adhesion test
A.A. Volinsky et al. / Acta Materialia 50 (2002) 441–466
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Interface Fracture Toughness Tests ‐ Bending
Asymmetric Double Cantilever Beam
Brazil‐Nut‐Sandwich
Single Leg Bending
Symmetric Double Cantilever Beam
4‐point bending
Asymmetric DCB
Asymmetric End‐Notched Flexure
End‐Notched Flexure
Sundaraman, Sitaraman 1997
Center Cracked Beam
Yeung, Lam, Yuen 2000
Double Cantilever Beam
Miller, Ho 2000
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Mode Separation/Evaluation –Critical ERR and Phase Angle
Measured
fracture
toughness
failure
region
Calculated
crack
loading
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Mode Separation/Evaluation –Critical ERR and Phase Angle
1
1
G c
G
IC
sin
2
With (a further material/interface parameter) is
a function of temperature and moisture
concentration
G c
failure
region
G() initiationi i i
G()
no initiation
Hutchinson and Suo, "Mixed Mode Cracking in Layered
Materials", Advances in Applied Mechanics, Vol. 29, pp.
63-191
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
K. Liechti, Adhesion Measurements Relative to Electronic
Packaging, Proc. 4th Annual Topical Conference On
Reliability, October 30 - November 1, 2000
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Nano‐Indentation for Interface Fracture Toughness Evaluation
• Nanoindentation for “measuring“ Young’s
modulus and hardness
• Nanoindentation for “measuring“ fracture
toughness
Buckling
• Nanoindentation for “measuring“ interfacial
fracture toughness (adhesion) – Conical and
wedge indenters
For instance:
E.E. Gdoutos, A. Volinsky, Interfacial Fracture Toughness of Thin Films, Tutorial AC‐Conf., June 6, 2005
M. R. Begley, D. R. Mumm, A. G. Evan, J. W. Hutchinson, Analysis of a Wedge Impression Test for Measuring the Interface
Toughness Between Films/Coatings and Ductile Substrates, Acta mater. 48 (2000) 3211‐3220
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Stress State t Determination/Verification
ti ifi ti
Fitting modeling assumption with experimental results
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

TSV ‐ Stresses near the Surface –vs. Raman‐Spectroscopy
zz
rz
rr
M. Hecker, GlobalFoundries, Dresden
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Surface vs. Midd‐Stress rr
Surface - rr
Middle -
Middle - rr
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Summary
Multilevel lFE‐modelling of cracks in BEoL‐Struktures
For Chip Package Interaction and
Reflow ‐ leadfree bumping
Goal: Reliability enhancement
Utilizing fracture mechanics concepts (cohesive and adhesive) and/or
Damage mechanics approaches
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

What we need
Intensive experimental work necessary for
Evaluation of residual stresses from manufacturing,
Evaluation of the material behavior (constitutive, size dependent)
Characterization of the damage behavior of materials
Characterization of strength/toughness properties (fracture mechanics
characterization) of materials and materials interfaces
Verification of simulation results
Extensive simulation work necessary
Huge simulation models and computing resources
Theoretical work – delamination und fracture (CZM, XFEM), materials
behavior (SGPM)
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

What we Need for Helpful Simulation Results
Residual stress
characterization
Damage and fracture
characterization
Material behavior and property
characterization
Simulation results
verification
Jürgen Auersperg, D. Vogel, M.U. Lehr,
M. Grillberger, J. Oswald, S. Rzepka, B. Michel
Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka

Thank You for Your Attention!
ti Micro Materials Center Chemnitz
Heads: Prof. B. Michel and
Dr. Sven Rzepka