Space and phase resolved optical emission spectroscopic measurements reveal that in certain parameter regimes, inductively coupled radio-frequency driven plasmas exhibit three distinct operation modes. At low powers, the plasma operates as an alpha-mode capacitively coupled plasma driven through the dynamics of the plasma boundary sheath potential in front of the antenna. At high powers, the plasma operates in inductive mode sustained through induced electric fields due to the time varying currents and associated magnetic fields from the antenna. At intermediate powers, close to the often observed capacitive to inductive (E-H) transition regime, energetic electron avalanches are identified to play a significant role in plasma sustainment, similar to gamma-mode capacitively coupled plasmas. These energetic electrons traverse the whole plasma gap, potentially influencing plasma surface interactions as exploited in technological applications.

1.
M.
Osiac
,
T.
Schwarz-Selinger
,
D.
O’Connell
,
B.
Heil
,
Z. L.
Petrovic
,
M.
Turner
,
T.
Gans
, and
U.
Czarnetzki
,
Plasma Sources Sci. Technol.
16
,
355
(
2007
).
2.
M. A.
Lieberman
and
A. J.
Lichtenberg
,
Principles of Plasma Discharges and Materials Processing
, 2nd ed. (
Wiley, New York
,
2005
).
3.
M.
Schulze
,
D.
O’Connell
,
T.
Gans
,
P.
Awakowicz
, and
A.
Keudell
,
Plasma Sources Sci. Technol.
16
,
774
(
2007
).
4.
T.
Gans
,
M.
Osiac
,
D.
O’Connell
,
V.
Kadetov
,
U.
Czarnetzki
,
T.
Schwarz-Selinger
,
H.
Halfmann
, and
P.
Awakowicz
,
Plasma Phys. Controlled Fusion
47
,
A353
(
2005
).
5.
T.
Makabe
and
Z.
Petrović
,
Plasma Electronics: Applications in Microelectronic Device Fabrication
(
Taylor and Francis
,
New York
,
2006
).
6.
M. A.
Sobolewski
,
J. Vac. Sci. Technol. A
24
,
1892
(
2006
).
7.
C. S.
Corr
,
P. G.
Steen
, and
W. G.
Graham
,
Plasma Sources Sci. Technol.
12
(
2
),
265
(
2003
).
8.
M.
Watanabe
,
D.
Shaw
, and
G.
Collins
,
Appl. Phys. Lett.
79
,
2698
(
2001
).
9.
M.
Wang
and
M. J.
Kushner
,
J. Appl. Phys.
107
,
023308
(
2010
).
10.
U.
Kortshagen
,
N.
Gibson
, and
J.
Lawler
,
J. Physics D: Appl. Phys.
29
,
1224
(
1996
).
11.
A.
Daltrini
,
S.
Moshkalev
,
T.
Morgan
,
R.
Piejak
, and
W. G.
Graham
,
Appl. Phys. Lett.
92
,
061504
(
2008
).
12.
F.
Gao
,
S. X.
Zhao
,
X. S.
Li
, and
Y. N.
Wang
,
Phys. Plasmas
17
,
103507
(
2010
).
13.
V.
Godyak
and
A.
Khanneh
,
IEEE Trans. Plasma Sci.
14
(
2
),
112
(
1986
).
14.
P. A.
Miller
,
G. A.
Hebner
,
K. E.
Greenberg
, and
P. D.
Pochan
,
J. Res. Natl. Inst. Stand. Technol.
100
(
4
),
427
(
1995
).
15.
T.
Gans
,
D.
O’Connell
,
V.
Schulz-von der Gathen
, and
J.
Waskoenig
,
Plasma Sources Sci. Technol.
19
,
034010
(
2010
).
16.
D.
O’Connell
,
T.
Gans
,
E.
Semmler
, and
P.
Awakowicz
,
Appl. Phys. Lett.
93
,
081502
(
2008
).
17.
K.
Niemi
,
V.
Schulz-von der Gathen
, and
H.
Döbele
,
Plasma Sources Sci. Technol.
14
,
375
(
2005
).
18.
M.
Abdel-Rahman
,
T.
Gans
,
V.
Schulz-von der Gathen
, and
H. F.
Döbele
,
Plasma Sources Sci. Technol.
14
(
1
),
51
(
2005
).
19.
T.
Gans
,
V.
Schulz-von der Gathen
, and
H.
Döbele
,
Europhys. Lett.
66
,
232
(
2004
).
20.
K.
Dittmann
,
K.
Matyash
,
S.
Nemschokmichal
,
J.
Meichsner
, and
R.
Schneider
,
Contrib. Plasma Phys.
50
(
10
),
942
(
2010
).
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