We report the direct observation of electrochemical potential and local transport field variations near scatterers like grain boundaries, triple points, and voids in thin platinum films studied by scanning tunneling potentiometry. The field is highest at a void, followed by a triple point and a grain boundary. The local transport field near a void can even be four orders of magnitude higher than the macroscopic field, indicating that the void is the most likely place for an electromigration induced failure. The field build up for a particular type of scatterer depends on the grain connectivity. We estimate an average grain boundary reflection coefficient for the film from the temperature dependence of its resistivity.

Topics
Crystallographic defects, Electromigration, Electrochemical potential, Potentiometry
1.
E.
Arzt
,
O.
Kraft
,
W. D.
Nix
, and
J. E.
Sanchez
, Jr.,
J. Appl. Phys.
76
,
1563
(
1994
).
Google Scholar
 
2.
P.
Besser
,
M. C.
Madden
, and
P. A.
Flinn
,
J. Appl. Phys.
72
,
3792
(
1992
).
Google Scholar
 
3.
R.
Landauer
,
IBM J. Res. Dev.
1
,
223
(
1957
).
Google Scholar
 
4.
R.
Landauer
,
Phys. Rev. B
14
,
1474
(
1976
).
Google Scholar
 
5.
C. S.
Chu
and
R. S.
Sorbello
,
Phys. Rev. B
38
,
7260
(
1988
).
Google Scholar
 
6.
R. S.
Sorbello
,
Phys. Rev. B
39
,
4984
(
1989
).
Google Scholar
 
7.
P.
Muralt
and
D. W.
Pohl
,
Appl. Phys. Lett.
48
,
514
(
1986
).
Google Scholar
 
8.
J. R.
Kirtley
,
S.
Washburn
, and
M. J.
Brady
,
Phys. Rev. Lett.
60
,
1546
(
1988
).
Google Scholar
 
9.
M. A.
Schneider
,
M.
Wenderoth
,
A. J.
Heinrich
,
M. A.
Rosentreter
, and
R. G.
Ulbrich
,
Appl. Phys. Lett.
69
,
1327
(
1996
).
Google Scholar
 
10.
B. G.
Briner
,
R. M.
Feenstra
,
T. P.
Chin
, and
J. M.
Woodall
,
Phys. Rev. B
54
,
R5283
(
1996
).
Google Scholar
 
11.
Geetha Ramaswamy, Ph.D. thesis, Indian Institute of Science, Bangalore, India, May 1998 (unpublished).
12.
Geetha
Ramaswamy
,
A. K.
Raychaudhuri
,
K.
Das Gupta
, and
G.
Sambandamurthy
,
Appl. Phys. A: Solids Surf.
66
,
S435
(
1998
).
Google Scholar
 
13.
J. R.
Sambles
,
Thin Solid Films
106
,
321
(
1983
).
Google Scholar
 
14.
Geetha
Ramaswamy
,
A. K.
Raychaudhuri
,
J.
Goswami
, and
S. A.
Shivashankar
,
J. Appl. Phys.
82
,
3797
(
1997
).
Google Scholar
 
15.
M. J.
Attardo
and
R.
Rosenberg
,
J. Appl. Phys.
41
,
2381
(
1970
).
Google Scholar
 
16.
P. S.
Ho
and
T.
Kwok
,
Rep. Prog. Phys.
52
,
301
(
1989
), and references therein.
Google Scholar
 
17.
M. Buttiker, Department of Theoretical Physics, University of Geneva, Switzerland.
This content is only available via PDF.
© 1999 American Institute of Physics.
1999
American Institute of Physics
You do not currently have access to this content.