In this work, we investigate the effect of different chemical treatments, such as solvents, bases, and acids, on the surface properties and electrical behavior of Schottky diodes fabricated on metalorganic chemical vapor deposition-grown, n-type, N-polar GaN. The I–V and C–V barrier heights of the as-grown Schottky diodes are found to be 0.40 eV and 0.60 eV, respectively, with an ideality factor n = 1.07. It is found that the solvent treatments neither change the surface nor the electrical performance of the Schottky diodes, as expected. However, the treatments by the alkaline photolithography developer and acid—the latter of which is often used to clean the surface of Ga-polar GaN films prior to metal contact deposition—degrade the performance of N-polar GaN. These base and acid treatments severely roughen the surface by creating triangular/hexagonal crystallographic facets. The I–V and C–V barrier heights of these base- and acid-treated diodes are increased to 0.63 eV and 1.00 eV, respectively, with ideality factor values n < 1.2. X-ray photoelectron spectroscopy studies indicate that base- and acid-treated surfaces have lower oxygen content as compared to the as-grown sample surface. It is understood that the increment in the barrier height for base- and acid-treated diodes could be due to the change in polarity, from N-polar to semi-polar/non-polar, on these crystallographic features. All these results demonstrate that, unlike for Ga-polar GaN, the N-polar GaN surface is highly reactive to bases and acids.

1.
P.
Hacke
,
T.
Detchprohm
,
K.
Hiramatsu
, and
N.
Sawaki
,
Appl. Phys. Lett.
63
,
2676
(
1993
).
2.
L.
Wang
,
M. I.
Nathan
,
T.
Lim
,
M. A.
Khan
, and
Q.
Chen
,
Appl. Phys. Lett.
68
,
1267
(
1996
).
3.
U.
Karrer
,
O.
Ambacher
, and
M.
Stutzmann
,
Appl. Phys. Lett.
77
,
2012
(
2000
).
4.
F.
Iucolano
,
F.
Roccaforte
,
F.
Giannazzo
, and
V.
Raineri
,
J. Appl. Phys.
102
,
113701
(
2007
).
5.
P. K.
Rao
,
B.
Park
,
S.-T.
Lee
,
Y.-K.
Noh
,
M.-D.
Kim
, and
J.-E.
Oh
,
J. Appl. Phys.
110
,
013716
(
2011
).
6.
J. D.
Guo
,
F. M.
Pan
,
M. S.
Feng
,
R. J.
Guo
,
P. F.
Chou
, and
C. Y.
Chang
,
J. Appl. Phys.
80
,
1623
(
1996
).
7.
L. S.
Yu
,
Q. Z.
Liu
,
Q. J.
Xing
,
D. J.
Qiao
,
S. S.
Lau
, and
J.
Redwing
,
J. Appl. Phys.
84
,
2099
(
1998
).
8.
A. R.
Arehart
,
B.
Moran
,
J. S.
Speck
,
U. K.
Mishra
,
S. P.
DenBaars
, and
S. A.
Ringel
,
J. Appl. Phys.
100
,
023709
(
2006
).
9.
P.
Reddy
,
B.
Sarkar
,
F.
Kaess
,
M.
Gerhold
,
E.
Kohn
,
R.
Collazo
, and
Z.
Sitar
,
Appl. Phys. Lett.
110
,
011603
(
2017
).
10.
E. H.
Rhoderick
and
R. H.
Williams
,
Metal-Semiconductor Contacts
(
Clarendon Press, Oxford University Press
,
Oxford
,
1988
).
11.
W.-C.
Yang
,
B. J.
Rodriguez
,
M.
Park
,
R. J.
Nemanich
,
O.
Ambacher
, and
V.
Cimalla
,
J. Appl. Phys.
94
,
5720
(
2003
).
12.
H.
Kim
,
S.-N.
Lee
,
Y.
Park
,
J. S.
Kwak
, and
T.-Y.
Seong
,
Appl. Phys. Lett.
93
,
032105
(
2008
).
13.
H. W.
Jang
,
J.-H.
Lee
, and
J.-L.
Lee
,
Appl. Phys. Lett.
80
,
3955
(
2002
).
14.
P.
Reddy
,
I.
Bryan
,
Z.
Bryan
,
W.
Guo
,
L.
Hussey
,
R.
Collazo
, and
Z.
Sitar
,
J. Appl. Phys.
116
,
123701
(
2014
).
15.
A.
Rizzi
and
H.
Lüth
,
Appl. Phys. Lett.
80
,
530
(
2002
).
16.
Z.-Q.
Fang
,
D. C.
Look
,
P.
Visconti
,
D.-F.
Wang
,
C.-Z.
Lu
,
F.
Yun
,
H.
Morkoç
,
S. S.
Park
, and
K. Y.
Lee
,
Appl. Phys. Lett.
78
,
2178
(
2001
).
17.
J.
Osvald
,
J.
Kuzmik
,
G.
Konstantinidis
,
P.
Lobotka
, and
A.
Georgakilas
,
Microelectron. Eng.
81
,
181
(
2005
).
18.
B. P.
Downey
,
D. J.
Meyer
,
D. S.
Katzer
,
D. F.
Storm
, and
S. C.
Binari
,
Solid State Electron.
86
,
17
(
2013
).
19.
P.
Reddy
,
D.
Khachariya
,
D.
Szymanski
,
M. H.
Breckenridge
,
B.
Sarkar
,
S.
Pavlidis
,
R.
Collazo
,
Z.
Sitar
, and
E.
Kohn
,
Semicond. Sci. Technol.
35
,
055007
(
2020
).
20.
Q. Z.
Liu
and
S. S.
Lau
,
Solid State Electron.
42
,
677
(
1998
).
21.
C.
Huh
,
S.-W.
Kim
,
H.-S.
Kim
,
I.-H.
Lee
, and
S.-J.
Park
,
J. Appl. Phys.
87
,
4591
(
2000
).
22.
O.
Ambacher
,
J.
Smart
,
J. R.
Shealy
,
N. G.
Weimann
,
K.
Chu
,
M.
Murphy
,
W. J.
Schaff
,
L. F.
Eastman
,
R.
Dimitrov
, and
L.
Wittmer
,
J. Appl. Phys.
85
,
3222
(
1999
).
23.
S.
Rajan
,
A.
Chini
,
M. H.
Wong
,
J. S.
Speck
, and
U. K.
Mishra
,
J. Appl. Phys.
102
,
044501
(
2007
).
24.
M. H.
Wong
,
Y.
Pei
,
T.
Palacios
,
L.
Shen
,
A.
Chakraborty
,
L. S.
McCarthy
,
S.
Keller
,
S. P.
DenBaars
,
J. S.
Speck
, and
U. K.
Mishra
,
Appl. Phys. Lett.
91
,
232103
(
2007
).
25.
C. R.
English
,
V. D.
Wheeler
,
N. Y.
Garces
,
N.
Nepal
,
A.
Nath
,
J. K.
Hite
,
M. A.
Mastro
, and
C. R.
Eddy
,
J. Vac. Sci. Technol. B
32
,
03D106
(
2014
).
26.
D.
Wei
,
T.
Hossain
,
D. P.
Briggs
, and
J. H.
Edgar
,
ECS J. Solid State Sci. Technol.
3
,
N127
(
2014
).
27.
H.
Kim
,
J.-H.
Ryou
,
R. D.
Dupuis
,
S.-N.
Lee
,
Y.
Park
,
J.-W.
Jeon
, and
T.-Y.
Seong
,
Appl. Phys. Lett.
93
,
192106
(
2008
).
28.
J.-Y.
Duboz
,
F.
Binet
,
N.
Laurent
,
E.
Rosencher
,
F.
Scholz
,
V.
Harle
,
O.
Briot
,
B.
Gil
, and
R. L.
Aulombard
,
MRS Proc.
449
,
1085
(
1996
).
29.
R.
Collazo
,
S.
Mita
,
A.
Rice
,
R. F.
Dalmau
, and
Z.
Sitar
,
Appl. Phys. Lett.
91
,
212103
(
2007
).
30.
R.
Kirste
,
R.
Collazo
,
G.
Callsen
,
M. R.
Wagner
,
T.
Kure
,
J.
Sebastian Reparaz
,
S.
Mita
,
J.
Xie
,
A.
Rice
,
J.
Tweedie
,
Z.
Sitar
, and
A.
Hoffmann
,
J. Appl. Phys.
110
,
093503
(
2011
).
31.
L. L.
Smith
,
S. W.
King
,
R. J.
Nemanich
, and
R. F.
Davis
,
J. Electron. Mater.
25
,
805
(
1996
).
32.
R.
France
,
T.
Xu
,
P.
Chen
,
R.
Chandrasekaran
, and
T. D.
Moustakas
,
Appl. Phys. Lett.
90
,
062115
(
2007
).
33.
B. B.
Haidet
,
B.
Sarkar
,
P.
Reddy
,
I.
Bryan
,
Z.
Bryan
,
R.
Kirste
,
R.
Collazo
, and
Z.
Sitar
,
Jpn. J. Appl. Phys.
56
,
100302
(
2017
).
34.
D.
Briggs
and
M. P.
Seah
,
Practical Surface Analysis by Auger and X-Ray Photoelectron Spectroscopy
(
Wiley
,
1983
).
35.
D. K.
Schroder
,
Semiconductor Material and Device Characterization
, 3rd ed. (
John Wiley & Sons
,
2006
).
36.
H. S.
Craft
,
A. L.
Rice
,
R.
Collazo
,
Z.
Sitar
, and
J.-P.
Maria
,
Appl. Phys. Lett.
98
,
082110
(
2011
).
37.
L.
Wang
,
Z.
Liu
,
E.
Guo
,
H.
Yang
,
X.
Yi
, and
G.
Wang
,
ACS Appl. Mater. Interfaces
5
,
5797
(
2013
).
38.
P.
Reddy
and
J.
Kumar
,
Semicond. Sci. Technol.
34
,
035004
(
2019
).
39.
J. H.
Werner
and
H. H.
Güttler
,
J. Appl. Phys.
69
,
1522
(
1991
).
40.
R. T.
Tung
,
Appl. Phys. Lett.
58
,
2821
(
1991
).
You do not currently have access to this content.