This paper is focused on evaluating the dominant factor for electromigration (EM) in sputtered high purity Al films. A closed-form equation of atomic flux divergence by treating grain boundary diffusion and hillock formation in a polycrystalline structure without passivation layer was derived to construct the theoretical model. According to the developed equation, it is available to see the effect of various parameters on the EM resistance. Moreover, based on the proposed model, we compared the EM resistance of different sputtered high purity Al films. These films differ in purity and features, which are realized as affecting factors for the EM resistance. Finally, according to the analysis by the synthesis of the obtained EM resistance, the evaluation of the dominant factor for EM in sputtered high purity Al films was approached. Although the effects of the average grain size and the effective valence cannot be ignored, the difference in diffusion coefficient was believed to have a dominant influence in determining the EM resistance. Thus, increasing the activation energy for grain boundary diffusion can significantly reduce the damage during EM in such sputtered polycrystalline Al films.

1.
Van Horn
,
K. R.
, 1967,
Aluminum, Vol. I. Properties, Physical Metallurgy and Phase Diagrams
,
American Society for Metals
,
Metals Park, OH
, Chap. 1.
2.
Grabe
,
B.
, and
Schreiber
,
H. -U.
, 1983, “
Lifetime and Drift Velocity Analysis for Electromigration in Sputtered Al Films, Multilayers, and Alloys
,”
Solid-State Electron.
0038-1101,
26
, pp.
1023
1032
.
3.
Black
,
J. R.
, 1969, “
Electromigration Failure Modes in Aluminum Metallization for Semiconductor Devices
,”
Proc. IEEE
0018-9219,
57
, pp.
1587
1594
.
4.
Nikawa
,
K.
, 1981, “
Monte Carlo Calculations Based on the Generalized Electromigration Failure Model
,”
Proceedings of the 1981 International Reliability Physics Symposium Conference
,
IEEE
,
Piscataway, NJ
, pp.
175
181
.
5.
Kirchheim
,
R.
, and
Kaeber
,
U.
, 1991, “
Atomistic and Computer Modeling of Metallization Failure of Integrated Circuits by Electromigration
,”
J. Appl. Phys.
0021-8979,
70
, pp.
172
181
.
6.
Goldstein
,
R. V.
,
Sarychev
,
M. E.
,
Shirabaikin
,
D. B.
,
Vladimirov
,
A. S.
, and
Zhitnikov
,
Yu. V.
, 2001, “
Modeling Electromigration and the Void Nucleation in Thin-Film Interconnects of Integrated Circuits
,”
Int. J. Fract.
0376-9429,
109
, pp.
91
121
.
7.
Nemoto
,
T.
,
Yokobori
,
A. T.
, Jr.
, and
Murakawa
,
T.
, 2006, “
A Theoretical Analysis of Electromigration Failure in Aluminum Interconnections
,”
Jpn. J. Appl. Phys., Part 1
0021-4922,
45
, pp.
5716
5719
.
8.
Abé
,
H.
,
Sasagawa
,
K.
, and
Saka
,
M.
, 2006, “
Electromigration Failure of Metal Lines
,”
Int. J. Fract.
0376-9429,
138
, pp.
219
240
.
9.
Saka
,
M.
,
Kato
,
K.
,
Tohmyoh
,
H.
, and
Sun
,
Y.
, 2008, “
Controlling Electromigration to Selectively Form Thin Metal Wires and Metal Microspheres
,”
J. Mater. Res.
0884-2914,
23
, pp.
3122
3128
.
10.
Attardo
,
M. J.
, and
Rosenberg
,
R.
, 1970, “
Electromigration Damage in Aluminum Film Conductors
,”
J. Appl. Phys.
0021-8979,
41
, pp.
2381
2386
.
11.
Howard
,
J. K.
,
White
,
J. F.
, and
Ho
,
P. S.
, 1978, “
Intermetallic Compounds of Al and Transitions Metal: Effect of Electromigration in 1–2-μm-Wide Lines
,”
J. Appl. Phys.
0021-8979,
49
, pp.
4083
4093
.
12.
Vaidya
,
S.
, and
Sinha
,
A. K.
, 1981, “
Effect of Texture and Grain Structure on Electromigration in Al-0.5%Cu Thin Films
,”
Thin Solid Films
0040-6090,
75
, pp.
253
259
.
13.
Patrinos
,
A. J.
, and
Schwarz
,
J. A.
, 1991, “
The Effect of Microstructure on the Resistance to Electromigration of Al-Cu Thin Film Conductors
,”
Thin Solid Films
0040-6090,
196
, pp.
47
63
.
14.
Fionova
,
L. K.
,
Kononenko
,
O. V.
, and
Matveev
,
V. N.
, 1993, “
The Structure and Electromigration Behavior of Aluminum Films Deposited by the Partially Ionized Beam Technique
,”
Thin Solid Films
0040-6090,
227
, pp.
54
58
.
15.
Hu
,
C. -K.
, 1995, “
Electromigration Failure Mechanisms in Bamboo-Grained Al(Cu) Interconnections
,”
Thin Solid Films
0040-6090,
260
, pp.
124
134
.
16.
Tu
,
K. N.
, 2003, “
Recent Advances on Electromigration in Very-Large-Scale-Integration of Interconnects
,”
J. Appl. Phys.
0021-8979,
94
, pp.
5451
5473
.
17.
Saka
,
M.
,
Kohara
,
T.
,
Hasegawa
,
T.
, and
Yamashita
,
M.
, 2009, “
A Simple Method for Testing the Electromigration Resistance of Solders
,”
Microsyst. Technol.
0946-7076,
15
, pp.
17
25
.
18.
Yeh
,
Y. T.
,
Chou
,
C. K.
,
Hsu
,
Y. C.
,
Chen
,
C.
, and
Tu
,
K. N.
, 2005, “
Threshold Current Density of Electromigration in Eutectic SnPb Solder
,”
Appl. Phys. Lett.
0003-6951,
86
, p.
203504
.
19.
Huntington
,
H. B.
, and
Grone
,
A. R.
, 1961, “
Current-Induced Marker Motion in Gold Wires
,”
J. Phys. Chem. Solids
0022-3697,
20
, pp.
76
87
.
20.
Blech
,
I. A.
, 1976, “
Electromigration in Thin Aluminum Films on Titanium Nitride
,”
J. Appl. Phys.
0021-8979,
47
, pp.
1203
1208
.
21.
Sasagawa
,
K.
,
Nakamura
,
N.
,
Saka
,
M.
, and
Abé
,
H.
, 1998, “
A New Approach to Calculate Atomic Flux Divergence by Electromigation
,”
ASME J. Electron. Packag.
1043-7398,
120
, pp.
360
366
.
22.
Sasagawa
,
K.
,
Naito
,
K.
,
Saka
,
M.
, and
Abé
,
H.
, 1999, “
A Method to Predict Electromigration Failure of Metal Lines
,”
J. Appl. Phys.
0021-8979,
86
, pp.
6043
6051
.
23.
Sasagawa
,
K.
,
Naito
,
K.
,
Kimura
,
H.
,
Saka
,
M.
, and
Abé
,
H.
, 2000, “
Experimental Verification of Prediction Method for Electromigration Failure of Polycrystalline Lines
,”
J. Appl. Phys.
0021-8979,
87
, pp.
2785
2791
.
24.
Saka
,
M.
,
Sun
,
Y. X.
, and
Reaz Ahmed
,
S.
, 2009, “
Heat Conduction in a Symmetric Body Subjected to a Current Flow of Symmetric Input and Output
,”
Int. J. Therm. Sci.
1290-0729,
48
, pp.
114
121
.
25.
Shinzawa
,
T.
, and
Ohta
,
T.
, 1998, “
Molecular Dynamics Simulation of Al Grain Boundary Diffusion for Electromigration Failure Analysis
,”
Proceedings of the 1998 International Interconnect Technology Conference
,
IEEE
,
Piscataway, NJ
, pp.
30
32
.
27.
Hasegawa
,
T.
,
Saka
,
M.
, and
Watanabe
,
Y.
, 2006, “
Direct Measurement of Local Surface Temperature of Eutectic Solder for Determining Electromigration Pattern
,”
J. Electron. Mater.
0361-5235,
35
, pp.
1074
1081
.
28.
Saka
,
M.
, and
Hasegawa
,
T.
, 2009, “
A Technique Utilizing Chemical Reagents for Direct Measurement of Temperature at a Local Area and Its Engineering Applications
,”
Acta Mech. Sin.
0459-1879,
25
, pp.
149
160
.
29.
Sim
,
S. P.
, 1979, “
Procurement Specification Requirements for Protection Against Electromigration Failures in Aluminum Metallizations
,”
Microelectron. Reliab.
0026-2714,
19
, pp.
207
218
.
30.
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
, pp.
3790
3799
.
31.
Kononenko
,
O. V.
,
Ivanov
,
E. D.
,
Matveev
,
V. N.
, and
Khodos
,
I. I.
, 1995, “
Electromigration Activation Energy in Pure Aluminum Films Deposited by Partially Ionized Beam Technique
,”
Scr. Metall. Mater.
0956-716X,
33
, pp.
1981
1986
.
32.
Spolenak
,
R.
,
Kraft
,
O.
, and
Arzt
,
E.
, 1998, “
Effect of Alloying Elements on Electromigration
,”
Microelectron. Reliab.
0026-2714,
38
, pp.
1015
1020
.
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