Nonlinear unloading behavior has been observed in thin metal films on substrates. In the present work, the effects of this nonlinear unloading behavior on the strain energy release rate in bilayer decohesion experiments, in which a highly stressed overlayer (“driver”) is used to decohere a layer (“target”) from a substrate, is modeled. Cases where either the driver or the target layer are nonlinear are considered. For particular combinations of stiffnesses and thicknesses, the difference between linear and nonlinear unloading behavior can be quite large (several hundred percent) at experimentally observed stress levels. For practical cases of CR/CU and CU/glass driver/target layer combinations, the maximum difference is about 25%.

Issue Section:
Technical Papers
Keywords:
elasticity, metallic thin films, adhesion, substrates, elastic deformation
Topics:
Elasticity, Glass, Metals, Stress, Nonmetallic materials, Fracture (Materials), Adhesion
1.
Hu
,
M. S.
,
Thouless
,
M. D.
, and
Evans
,
A. G.
,
1988
, “
The Decohesion of Thin Films From Brittle Substrates
,”
Acta Metall.
,
36
, pp.
1301
–
1307
.
2.
Drory
,
M. D.
,
Thouless
,
M. D.
, and
Evans
,
A. G.
,
1988
, “
On the Decohesion of Residually Stressed Thin Films
,”
Acta Metall.
,
36
, pp.
2019
–
2028
.
3.
Suo
,
Z.
, and
Hutchinson
,
J. W.
,
1989
, “
Steady-State Cracking in Brittle Substrates Beneath Adherent Films
,”
Int. J. Solids Struct.
,
25
, pp.
1337
–
1353
.
4.
Evans
,
A. G.
, and
Dalgleish
,
B. J.
,
1992
, “
The Fracture Resistance of Metal-Ceramic Interfaces
,”
Acta Metall. Mater.
,
40
, pp.
S295–S305
S295–S305
.
5.
Bagchi
,
A.
,
Lucas
,
G. E.
,
Suo
,
Z.
, and
Evans
,
A. G.
,
1994
, “
A New Procedure for Measuring the Decohesion Energy for Thin Ductile Films on Substrates
,”
J. Mater. Res.
,
9
, pp.
1734
–
1741
.
6.
Kriese
,
M. D.
,
Gerberich
,
W. W.
, and
Moody
,
N. R.
,
1999
, “
Quantitative Adhesion Measures of Multilayer Films: Part II. Indentation of W/Cu, W/W, Cr/W
,”
J. Mater. Res.
,
14
, pp.
3019
–
3026
.
7.
Lane
,
M.
, and
Dauskardt
,
R. H.
,
2000
, “
Adhesion and Reliability of Copper Interconnects With Ta and TaN Barrier Layers
,”
J. Mater. Res.
,
15
, pp.
203
–
211
.
8.
Baker, S. P., Keller, R.-M., and Arzt, E., 1998, “Energy Storage and Recovery in Thin Metal Films on Substrates,” Proceedings, Thin Films: Stresses and Mechanical Properties VII, R. C. Cammarata et al. eds., Materials Research Society, Warrendale PA, pp. 605–610.
9.
Shu, J., Clyburn, S., Mates, T., and Baker, S. P., 1999, “Effects of Thickness and Oxygen Content on Thermomechanical Behavior of Thin Cu Gilms Passivated With AlN,” Proceedings, Materials Reliability in Microelectronics IX, D. D. Brown, et al., eds., Materials Research Society, Pittsburgh, PA, pp. 707–712.
10.
Keller
,
R.-M.
,
Baker
,
S. P.
, and
Arzt
,
E.
,
1998
, “
Quantitative Analysis of Strengthening Mechanisms in Thin Cu films: Effects of Film Thickness, Grain Size and Passivation
,”
J. Mater. Res.
,
13
, pp.
1307
–
1317
.
11.
Wang, X., 2000, “Bilayer Modeling and Measurements of Adhesion of Copper Thin Films to Glass,” M.S. thesis, Cornell University, Ithaca, NY.
Copyright © 2002
 by ASME
You do not currently have access to this content.