This paper investigates the spatial and temporal variation in plasma electron density over a region between 5 and 10cm above the race-track region of a pulsed magnetron sputtering target. The pulse operation is performed using an asymmetric bipolar pulsed dc power supply, which provides a sequence of large negative “on-phase” voltage (350V) and a small positive “reverse-phase” voltage (+10V) for 55% of the pulse duration (10μs). The electron density is measured using a floating microwave hairpin resonance probe. The results show electron expulsion from the target in the initial on phase, which propagates with a characteristic speed exceeding the ion thermal speed. In the steady state on phase, a consistent higher density is observed. A quantitative model has been developed to explain the resultant density drops in the initial on phase. While in the reverse phase, we observed an anomalous growth in density at a specific location from the target (d>7cm). The mechanism behind the increase in electron density has been attributed to the modulation in spatial plasma potential, which was measured earlier in the same apparatus using a floating emissive probe [J. W. Bradley et al, Plasma Sources Sci. Technol.13, 189 (2004)].

1.
J. W.
Bradley
,
S. K.
Karkari
, and
A.
Vetushka
,
Plasma Sources Sci. Technol.
13
,
189
(
2004
).
2.
H.
Bartzsch
,
P.
Frach
,
K.
Goedicke
, and
Chr.
Gottfried
,
Surf. Coat. Technol.
120–121
,
723
(
1999
).
3.
P. J.
Kelly
and
R. D.
Arnell
,
J. Vac. Sci. Technol. A
17
,
945
(
1999
).
4.
J.
Musil
,
J.
Leština
,
J.
Vlček
, and
T.
Tolg
,
J. Vac. Sci. Technol. A
19
,
420
(
2001
).
5.
S.-H.
Seo
,
J.-H.
In
, and
H.-Y.
Chang
,
Appl. Phys. Lett.
86
,
262103
(
2005
).
6.
J. T.
Gudmundsson
,
J.
Alami
, and
U.
Helmersson
,
Appl. Phys. Lett.
78
,
3427
(
2001
).
7.
J. T.
Gudmundsson
,
J.
Alami
, and
U.
Helmersson
,
Surf. Coat. Technol.
161
,
249
(
2002
).
8.
V.
Kouznetzov
,
K.
Macàk
,
J. M.
Schneider
,
U.
Helmersson
, and
I.
Petrov
,
Surf. Coat. Technol.
122
,
290
(
1999
).
9.
K.
Macàk
,
V.
Kouznetzov
,
J. M.
Schnider
,
U.
Helmersson
, and
I.
Petrov
,
J. Vac. Sci. Technol. A
18
,
1533
(
2000
).
10.
S.
Schiller
,
K.
Goedicke
,
J.
Reshke
,
V.
Kirchhoff
,
S.
Schneider
, and
F.
Milde
,
Surf. Coat. Technol.
61
,
331
(
1993
).
11.
J. W.
Bradley
,
G. C. B.
Clarke
,
N. St. J.
Braithwaite
,
P. M.
Bryant
, and
P. J.
Kelly
,
Plasma Sources Sci. Technol.
15
,
S44
(
2006
).
12.
H.
Bartzsch
,
D.
Gloß
,
B.
Bocher
,
P.
Frach
, and
K.
Goedicke
,
Surf. Coat. Technol.
174–175
,
774
(
2003
).
13.
J. W.
Bradley
,
H.
Bäcker
,
P. J.
Kelly
, and
R. D.
Arnell
,
Surf. Coat. Technol.
135
,
221
(
2000
).
14.
J. W.
Bradley
,
H.
Bäcker
,
P. J.
Kelly
, and
R. D.
Arnell
,
Surf. Coat. Technol.
142–144
,
337
(
2001
).
15.
S. K.
Karkari
,
A.
Vetushka
, and
J. W.
Bradley
,
J. Vac. Sci. Technol. A
21
,
L
28
(
2003
).
16.
A.
Vetushka
,
S. K.
Karkari
, and
J. W.
Bradley
,
J. Vac. Sci. Technol. A
22
,
2459
(
2004
).
17.
J.
Lopez
,
W.
Zhu
,
A.
Freilich
,
A.
Belkind
, and
K.
Becker
,
J. Phys. D
38
,
1769
(
2005
).
18.
S. K.
Karkari
,
H.
Backer
,
D.
Forder
, and
J. W.
Bradley
,
Meas. Sci. Technol.
13
,
1431
(
2002
).
19.
M.
Misina
,
J. W.
Bradley
,
H.
Backer
,
Y.
Aranda-Gonzalvo
,
S. K.
Karkari
, and
D.
Forder
,
Vacuum
68
,
171
(
2003
).
20.
J. W.
Bradley
,
H.
Backer
,
Y.
Aranda-Gonzalvo
,
P. J.
Kelly
, and
R. D.
Arnell
,
Plasma Sources Sci. Technol.
11
,
165
(
2002
).
21.
G.
Ding
,
J. E.
Scharer
, and
K. L.
Kelly
,
J. Appl. Phys.
84
,
1236
(
1998
).
22.
F.
Richter
,
T.
Welzel
,
T.
Dunger
, and
H.
Kupfer
,
Surf. Eng.
20
,
163
(
2004
).
23.
S.
Karkari
and
J. W.
Bradley
,
Proceedings of the 48th Annual S.V.C. Technical Conference and Smart Materials Symposium
, Colorado, 23–28 April,
2005
, p.
491
.
24.
S. K.
Karkari
and
A. R.
Ellingboe
,
Appl. Phys. Lett.
88
,
101501
(
2006
).
25.
S. K.
Karkari
,
C.
Gaman
,
A. R.
Ellingboe
,
I.
Swindells
, and
J. W.
Bradley
,
Meas. Sci. Technol.
18
,
2649
(
2007
).
26.
V.
Milosavljević
,
S. K.
Karkari
, and
A. R.
Ellingboe
,
Plasma Sources Sci. Technol.
16
,
304
(
2007
).
27.
M. A.
Lieberman
and
A. J.
Lichtenberg
,
Principles of Plasma Discharges and Materials Processing
, 1st ed., (
Willey
,
New York
,
1994
).
28.
R. L.
Stenzel
,
Rev. Sci. Instrum.
47
,
603
(
1976
).
29.
R. B.
Piejak
,
V. A.
Godyak
,
R.
Garner
,
B. M.
Alexandrovich
, and
N.
Sternberg
,
J. Appl. Phys.
95
,
3785
(
2004
).
30.
R. B.
Piejak
,
J.
Al-Kuzee
, and
A. St.
Braithwaite
,
Plasma Sources Sci. Technol.
14
,
734
(
2005
).
31.
F. F.
Chen
,
Introduction to Plasma Physics and Controlled Nuclear Fusion
, (
Plenum
,
New York
,
1984
), Vol.
1
.
32.
K. A.
Lonngren
M.
Khazei
,
E. F.
Gabl
, and
J. M.
Bulson
,
Plasma Phys.
24
,
1483
(
1982
).
You do not currently have access to this content.