We have grown high-crystallinity ZnO thin films on lattice-matched ScAlMgO4 substrates by pulsed-laser deposition with doping donor (Ga) and acceptor (N) simultaneously. Alternating ablation of ceramics with concentrated Ga addition and highly pure single crystal targets yielded in a controlled Ga concentration (CGa) in a wide range of 1018–1020cm−3 with minimal contamination of undesired impurities such as Al and Si. The use of the originally developed temperature-gradient method, where controlled and continuous gradient of the growth temperature is given to the single substrate with a range of about 50–200 °C, results in a continuous spread of N concentration (CN) in a controlled fashion. Therefore, the ratio of CN/CGa can be varied continuously in a wide range for each film, assuring that a region satisfying p-type codoping condition predicted by T. Yamamoto and H. K. Yoshida [Jpn. J. Appl. Phys., Part 2 38, L166 (1999)] is included in the sample. The electrical properties were measured for over thousand specimens of lithographically patterned Hall bars without observing any sign of p-type conduction.

1.
P.
Yu
,
Z. K.
Tang
,
G. K. L.
Wong
,
M.
Kawasaki
,
A.
Ohtomo
,
H.
Koinuma
, and
Y.
Segawa
,
Solid State Commun.
103
,
459
(
1997
).
2.
Z. K.
Tang
,
G. K. L.
Wong
,
P.
Yu
,
M.
Kawasaki
,
A.
Ohtomo
,
H.
Koinuma
, and
Y.
Segawa
,
Appl. Phys. Lett.
72
,
3270
(
1998
).
3.
D. M.
Bagnell
,
Y. F.
Chen
,
Z.
Zhu
,
T.
Yao
,
S.
Koyama
,
M. Y.
Shen
, and
T.
Goto
,
Appl. Phys. Lett.
70
,
2230
(
1997
).
4.
H. D.
Sun
,
T.
Makino
,
N. T.
Tuan
,
Y.
Segawa
,
Z. K.
Tang
,
G. K. L.
Wong
,
M.
Kawasaki
,
A.
Ohtomo
,
K.
Tamura
, and
H.
Koinuma
,
Appl. Phys. Lett.
77
,
4250
(
2000
).
5.
A.
Ohtomo
,
K.
Tamura
,
T.
Makino
,
Y.
Segawa
,
Z. K.
Tang
,
K. L.
Wong
,
Y.
Matsumoto
,
H.
Koinuma
, and
M.
Kawasaki
,
Appl. Phys. Lett.
77
,
2204
(
2000
).
6.
K.
Hümmer
,
Phys. Status Solidi B
56
,
249
(
1973
).
7.
K.
Minegishi
,
Y.
Koiwai
,
Y.
Kikuchi
,
K.
Yano
,
M.
Kasuga
, and
A.
Shimizu
,
Jpn. J. Appl. Phys., Part 2
36
,
L1453
(
1997
).
8.
X.-L.
Guo
,
H.
Tabata
, and
T.
Kawai
,
J. Cryst. Growth
233
,
135
(
2001
).
9.
Y. R.
Ryu
,
S.
Zhu
,
D. C.
Look
,
J. M.
Wrobel
,
H. M.
Joeng
, and
H. W.
White
,
J. Cryst. Growth
216
,
330
(
2000
).
10.
T.
Yamamoto
and
H. K.
Yoshida
,
Jpn. J. Appl. Phys., Part 2
38
,
L166
(
1999
).
11.
M.
Joseph
,
H.
Tabata
, and
T.
Kawai
,
Jpn. J. Appl. Phys., Part 2
38
,
L2505
(
1999
).
12.
M. Kawasaki, K. Tamura, K. Saikusa, T. Aita, A. Tsukazaki, A. Ohtomo, Z. G. Jin, Y. Matsumoto, T. Fukumura, H. Koinuma, Y. Ohmaki, S. Kishimoto, Y. Ohno, F. Matsukura, H. Ohno, T. Makino, N. T. Tuan, H. D. Sun, C. H. Chia, Y. Segawa, Z. K. Tang, and G. K. L. Wang, Ext. Abstract of 2000 Int’l. Conference on Solid State Devices and Materials, Sendai, Japan, 2000, p. 128. This claim was made based on unproper Hall measurements and the data were wrong as reported in the oral presentation of the conference and the annual meeting of Japanese Applied Physics Society, Sapporo, Japan, September, 2000 (unpublished).
13.
X. L.
Guo
,
J. H.
Choi
,
H.
Tabata
, and
T.
Kawai
,
Jpn. J. Appl. Phys., Part 2
40
,
L177
(
2001
).
14.
T.
Aoki
,
Y.
Hatanaka
, and
D. C.
Look
,
Appl. Phys. Lett.
76
,
3257
(
2000
).
15.
Y. R.
Ryu
,
W. J.
Kim
, and
H. W.
White
,
J. Cryst. Growth
219
,
419
(
2000
).
16.
A. Zunger (private communication).
17.
A.
Ohtomo
,
K.
Tamura
,
K.
Saikusa
,
K.
Takahashi
,
T.
Makino
,
Y.
Segawa
,
H.
Koinuma
, and
M.
Kawasaki
,
Appl. Phys. Lett.
75
,
2635
(
1999
).
18.
A.
Ohtomo
,
M.
Kawasaki
,
T.
Koida
,
K.
Masubuchi
,
H.
Koinuma
,
Y.
Sakurai
,
Y.
Yoshida
,
T.
Yasuda
, and
Y.
Segawa
,
Appl. Phys. Lett.
72
,
2466
(
1998
).
19.
K.
Tamura
,
A.
Ohtomo
,
K.
Saikusa
,
Y.
Osaka
,
T.
Makino
,
Y.
Segawa
,
M.
Sumiya
,
S.
Fuke
,
H.
Koinuma
, and
M.
Kawasaki
,
J. Cryst. Growth
214
,
59
(
2000
).
20.
M.
Ohtani
,
T.
Fukumura
,
M.
Kawasaki
,
K.
Omote
,
T.
Kikuchi
,
J.
Harada
,
A.
Ohtomo
,
M.
Lippmaa
,
T.
Ohnishi
,
D.
Komiyama
,
R.
Takahashi
,
Y.
Matsumoto
, and
H.
Koinuma
,
Appl. Phys. Lett.
79
,
3594
(
2001
).
21.
T.
Makino
,
T.
Yasuda
,
Y.
Segawa
,
A.
Ohtomo
,
K.
Tamura
,
M.
Kawasaki
, and
H.
Koinuma
,
Appl. Phys. Lett.
79
,
1282
(
2001
).
This content is only available via PDF.
You do not currently have access to this content.