A tunneling spectroscopy study is presented of superconducting MoN and Nb0.8Ti0.2N thin films grown by atomic layer deposition (ALD). The films exhibited a superconducting gap of 2 meV and 2.4 meV, respectively, with a corresponding critical temperature of 11.5 K and 13.4 K, among the highest reported Tc values achieved by the ALD technique. Tunnel junctions were obtained using a mechanical contact method with a Au tip. While the native oxides of these films provided poor tunnel barriers, high quality tunnel junctions with low zero bias conductance (below ∼10%) were obtained using an artificial tunnel barrier of Al2O3 on the film's surface grown ex situ by ALD. We find a large critical current density on the order of 4 × 106 A/cm2 at T = 0.8Tc for a 60 nm MoN film and demonstrate conformal coating capabilities of ALD onto high aspect ratio geometries. These results suggest that the ALD technique offers significant promise for thin film superconducting device applications.

1.
R. B.
van Dover
,
D. D.
Bacon
, and
W. R.
Sinclair
,
Appl. Phys. Lett.
41
,
764
(
1982
).
2.
D. D.
Bacon
,
A. T.
English
,
S.
Nakahara
,
F. G.
Peters
,
H.
Schreiber
,
W. R.
Sinclair
, and
R. B.
van Dover
,
J. Appl. Phys.
54
,
6509
(
1983
).
3.
S.
Thakoor
,
J. L.
Lamb
,
A. P.
Thakoor
, and
S. K.
Khanna
,
J. Appl. Phys.
58
,
4643
(
1985
).
4.
H.
Ihara
,
M.
Hirabayashi
,
K.
Senzaki
,
Y.
Kimura
, and
H.
Kezuka
,
Phys. Rev. B
32
,
1816
(
1985
).
5.
Y.
Zhang
,
N.
Haberkorn
,
F.
Ronning
,
H.
Wang
,
N. A.
Mara
,
M.
Zhuo
,
L.
Chen
,
J. H.
Lee
,
K. J.
Blackmore
,
E.
Bauer
,
A. K.
Burrell
,
T. M.
McCleskey
,
M. E.
Hawley
,
R. K.
Schulze
,
L.
Civale
,
T.
Tajima
, and
Q.
Jia
,
J. Am. Chem. Soc.
133
,
20735
(
2011
).
6.
Y. H.
Shi
,
B. R.
Zhao
,
Y. Y.
Zhao
,
L.
Li
, and
J. R.
Liu
,
Phys. Rev. B
38
,
4488
4491
(
1988
);
A. Y.
Ganin
,
L.
Kienle
, and
G. V.
Vajenine
,
J. Solid State Chem.
179
,
2339
(
2006
).
7.
K.
Inumaru
,
K.
Baba
, and
S.
Yamanaka
,
Chem. Mater.
17
,
5935
(
2005
);
K.
Inumaru
,
K.
Baba
, and
S.
Yamanaka
,
Phys. Rev. B
73
,
052504
(
2006
).
8.
K.
Inumaru
,
K.
Baba
, and
S.
Yamanaka
,
Appl. Surf. Sci.
253
,
2863
(
2006
).
9.
Y.
Uzawa
,
Z.
Wang
, and
A.
Kawakami
,
Appl. Phys. Lett.
73
,
680
(
1998
);
K. H.
Gundlach
and
M.
Schicke
,
Supercond. Sci. Technol.
13
,
R171
(
2000
);
N.
Iosad
,
V. V.
Roddatis
,
S. N.
Polyakov
,
A. V.
Varlashkin
,
B. D.
Jackson
,
P.
Dmitriev
,
J.
Gao
, and
T.
Klapwijk
,
IEEE Trans. Appl. Supercond.
11
,
3832
(
2001
).
10.
M.
Ritala
and
M.
Leskela
,
Handbook of Thin Film Materials
, edited by
H. S.
Nalwa
(
Academic Press
,
2001
), Vol.
1
.
11.
R. L.
Puurunen
,
J. Appl. Phys.
97
,
121301
(
2005
).
12.
J. A.
Klug
,
T.
Proslier
,
J. W.
Elam
,
R. E.
Cook
,
J. M.
Hiller
,
H.
Claus
,
N. G.
Becker
, and
M. J.
Pellin
,
J. Phys. Chem. C
115
,
25063
(
2011
);
T.
Proslier
,
J. A.
Klug
,
J. W.
Elam
,
H.
Claus
,
N. G.
Becker
, and
M. J.
Pellin
,
J. Phys. Chem. C
115
,
9477
(
2011
).
13.
L.
Hiltunen
,
M.
Leskelä
,
M.
Mäkelä
,
L.
Niinistö
,
E.
Nykänen
, and
P.
Soininen
,
Thin Solid Films
166
,
149
(
1988
).
14.
L.
Ozyuzer
,
J. F.
Zasadzinski
, and
K. E.
Gray
,
Cryogenics
38
,
911
(
1998
).
15.
G. E.
Blonder
,
M.
Tinkham
, and
T. M.
Klapwijk
,
Phys. Rev. B
25
,
4515
(
1982
);
R. C.
Dynes
,
V.
Narayanamurti
, and
J. P.
Garno
,
Phys. Rev. Lett.
41
,
1509
(
1978
).
16.
A.
Belkin
,
V.
Novosad
,
M.
Iavarone
,
R.
Divan
,
J.
Hiller
,
T.
Proslier
,
J. E.
Pearson
, and
G.
Karapetrov
,
Appl. Phys. Lett.
96
,
092513
(
2010
);
T.
Proslier
,
J.
Zasadzinski
,
J.
Moore
,
M.
Pellin
,
J.
Elam
,
L.
Cooley
,
C.
Antoine
,
J.
Norem
, and
K. E.
Gray
,
Appl. Phys. Lett.
93
,
192504
(
2008
).
17.
J.
Zasadzinski
,
D. M.
Burnell
,
E. L.
Wolf
, and
G. B.
Arnold
,
Phys. Rev. B
25
,
1622
(
1982
).
18.
M. D.
Groner
,
F. H.
Fabreguette
,
J. W.
Elam
, and
S. M.
George
,
Chem. Mater.
16
,
639
(
2004
).
19.
J. A.
Klug
,
N. G.
Becker
,
N. R.
Groll
,
C.
Cao
,
M. S.
Weimer
,
M. J.
Pellin
,
J. F.
Zasadzinski
, and
T.
Proslier
,
Appl. Phys. Lett.
103
,
211602
(
2013
);
J. W.
Elam
,
M. D.
Groner
, and
S. M.
George
,
Rev. Sci. Instrum.
73
,
2981
(
2002
).
20.
T.
Herzog
,
H. A.
Radovan
,
P.
Ziemann
, and
E. H.
Brandt
,
Phys. Rev. B
56
,
2871
(
1997
);
H.
Claus
,
U.
Welp
,
H.
Zheng
,
L.
Chen
,
A. P.
Paulikas
,
B. W.
Veal
,
K. E.
Gray
, and
G. W.
Crabtree
,
Phys. Rev. B
64
,
144507
(
2001
).
You do not currently have access to this content.