As the electronics industry continues to push for high performance and miniaturization, the demand for higher current densities, which may cause electromigration failures in an IC, interconnects. Electromigration is a phenomenon that metallic atoms constructing the line are transported by electron wind. The damage induced by electromigration appears as the formation of voids and hillocks. A numerical simulation method for electromigration void incubation, and afterwards, void propagation, based on commercial software ANSYS Multiphysics and FORTRAN code, is presented in this paper. The electronic migration formulation considering the effects of the electron wind force, stress gradients, temperature gradients, and the atomic concentration gradient has been developed for the electromigration failure mechanisms. Due to introducing the atomic concentration gradient driving force in atomic flux formulations, the conventional atomic flux divergence method is no longer valid in electromigration (EM) simulation. Therefore, the corresponding EM atomic concentration redistribution algorithm is proposed using FORTRAN code. Finally, the comparison of voids generation through the numerical example of a standard wafer electromigration accelerated test (SWEAT) structure with the measurement result is discussed.

Issue Section:
Research Papers
Keywords:
electromigration, failure analysis, voids (solid)
Topics:
Algorithms, Atoms, Density, Electrodiffusion, Simulation, Stress, Current density, Failure, Metals, Temperature
1.
Black
,
J. R.
, 1968, “
Mass Transport of Aluminum by Momentum Exchange With Conducting Electrons
,”
Proceedings of the Sixth Annual Reliability Physics Symposium Proceedings
, pp.
148
–
159
.
2.
Tu
,
K. N.
, 2003, “
Recent Advances on Electromigration in Every-Large-Scale-Integration of Interconnects
,”
J. Appl. Phys.
0021-8979,
94
(
9
), pp.
5451
–
5473
.
Crossref
Search ADS
 
3.
Liang
,
S. W.
,
Shao
,
T. L.
, and
Chen
,
C.
, 2005, “
3-D Simulation on Current Density Distribution in Flip-Chip Solder Joints With Thick Cu UBM Under Current Stressing
,”
Proceedings of the Electronic Components and Technology Conference
, pp.
1416
–
1420
.
4.
Korhonen
,
M. A.
,
Børgesen
,
P.
,
Tu
,
K. N.
, and
Li
,
C. Y.
, 1993, “
Stress Evolution Due to Electromigration in Confined Metal Lines
,”
J. Appl. Phys.
0021-8979,
73
(
8
), pp.
3790
–
3799
.
Crossref
Search ADS
 
5.
Lloyd
,
J. R.
,
Shatzkes
,
M.
, and
Challaner
,
D. C.
, 1988, “
Kinetic Study of Electromigration Failure in Cr/Al–Cu Thin Film Conductors Covered With Polyimide and the Problem of the Stress Dependent Activation Energy
,”
Proceedings of the Annual Proceedings-Reliability Physics (Symposium)
, pp.
216
–
225
.
6.
Tan
,
C. M.
, and
Roy
,
A.
, 2006, “
Investigation of the Effect of Temperature and Stress Gradients on Accelerated EM Test for Cu Narrow Interconnects
,”
Thin Solid Films
0040-6090,
504
(
1–2
), pp.
288
–
293
.
7.
Clement
,
J. J.
, and
Lloyda
,
J. R.
, 1992, “
Numerical Investigations of the Electromigration Boundary Value Problem
,”
J. Appl. Phys.
0021-8979,
71
(
4
), pp.
1729
–
1731
.
Crossref
Search ADS
 
8.
Dalleau
,
D.
, and
Weide-Zaage
,
K.
, 2001, “
Three-Dimensional Voids Simulation in Chip-Level Metallization Structures: A Contribution to Reliability Evaluation
,”
Microelectron. Reliab.
0026-2714,
41
(
9–10
), pp.
1625
–
1630
.
9.
Dalleau
,
D.
, and
Weide-Zaage
,
K.
, 2002, “
3-D Time-Depending Simulation of Void Formation in a SWEAT Metallization Structure
,”
Proceedings of the EuroSimE
, pp.
310
–
315
.
10.
Weide-Zaage
,
K.
,
Dalleau
,
D.
, and
Yu
,
X. B.
, 2003, “
Static and Dynamic Analysis of Failure Locations and Void Formation in Interconnects Due to Various Migration Mechanisms
,”
Mater. Sci. Semicond. Process.
1369-8001,
6
(
1–3
), pp.
85
–
92
.
11.
Liu
,
Y.
, and
Scott
,
I.
, 2003, “
Power Cycling Simulation of an IC Package: Considering Electromigration and Thermal-Mechanical Failure
,”
Proceedings of the 53rd Electronic Components and Technology Conference
, pp.
415
–
421
.
12.
Liang
,
L. H.
,
Xu
,
Y. J.
, and
Liu
,
Y.
, 2006, “
Electro-Migration Study in Solder Joint and Interconnects of IC Packages
,”
Proceedings of EuroSIME2006
, pp.
464
–
470
.
13.
Liang
,
L. H.
, and
Liu
,
Y.
, 2006, “
Reliability Study in Solder Joint Under Electromigration Thermal-Mechanical Load
,”
Proceedings of the 2006 Seventh International Conference on Electronic Packaging Technology
, pp.
861
–
866
.
14.
Tan
,
C. M.
,
Hou
,
Y. J.
, and
Li
,
W.
, 2007, “
Revisit to the Finite Element Modeling of Electromigration for Narrow Interconnects
,”
J. Appl. Phys.
0021-8979,
102
(
3
), p.
033705
.
Crossref
Search ADS
 
15.
Sukharev
,
V.
, and
Zschech
,
E.
, 2004, “
A Model for Electromigration-Induced Degradation Mechanisms in Dual-Inlaid Copper Interconnects: Effect of Interface Bonding Strength
,”
J. Appl. Phys.
0021-8979,
96
(
11
), pp.
6337
–
6343
.
Crossref
Search ADS
 
16.
Reddy
,
J. N.
, 2006,
An Introduction to the Finite Element Method
, 3rd ed.,
McGraw-Hill
,
New York
.
17.
Sasagawa
,
K.
,
Hasegawa
,
M.
,
Saka
,
M.
, and
Abe
,
H.
, 2002, “
Prediction of Electromigration Failure in Passivated Polycrystalline Line
,”
J. Appl. Phys.
0021-8979,
91
(
11
), pp.
9005
–
9014
.
Crossref
Search ADS
 
18.
Ye
,
H.
,
Basaran
,
C.
, and
Hopkins
,
D. C.
, 2003, “
Numerical Simulation of Stress Evolution During Electromigration in IC Interconnect Lines
,”
IEEE Trans. Compon. Packag. Technol.
1521-3331,
26
(
3
), pp.
673
–
681
.
Crossref
Search ADS
 
19.
Jeon
,
I.
, and
Park
,
Y. B.
, 2004, “
Analysis of the Reservoir Effect on Electromigration Reliability
,”
Microelectron. Reliab.
0026-2714,
44
, pp.
917
–
928
.
Crossref
Search ADS
 
Copyright © 2010
 by American Society of Mechanical Engineers
You do not currently have access to this content.