We comprehensively analyze the effects of the number and distribution of Al2O3 atomic layer deposition (ALD) cycles into a 10-nm-thick HfO2 matrix on the ferroelectric switching behavior. An ALD cycle containing one pulse for Hf (or Al) precursor and one pulse of water as reactant is repeated 150 times for the given thickness of 10 nm. Spontaneous remnant polarization (Pr) is enabled through the formation of crystalline Al-doped HfO2 (Al:HfO2) by incorporating at least two Al2O3 ALD cycles evenly into the HfO2 film under annealing at 600 °C for 3 min following W top electrode (TE) deposition. When more than four Al2O3 cycles are used, the Al elements function as leakage sources rather than stressors, resulting in an open hysteresis loop and a weak endurance of 105 cycles. Notably, an improved 2 Pr of ∼9 μC/cm2 is achieved when the Al2O3 layers are concentrated near the lower region of the HfO2. On the other hand, as the Al2O3 layers are intensively located in the upper region of the HfO2, a dielectric response is observed in the polarization–voltage and current–voltage measurements. Our results indicate that the two mechanical stresses induced by the Al dopant with a size smaller than Hf and the difference in the thermal expansion coefficient between TE and Al:HfO2 effectively activate both the lower and upper sites. Therefore, many dipoles are observed to participate in the polarization owing to the stresses that are applied evenly throughout the Al:HfO2 layer to form the orthorhombic phase.

1.
L. W.
Martin
and
A. M.
Rappe
,
Nat. Rev. Mater.
2
,
16087
(
2017
).
2.
A.
von Hippel
,
R. G.
Breckenridge
,
F. G.
Chesley
, and
L.
Tisza
,
Ind. Eng. Chem.
38
(
11
),
1097
1109
(
1946
).
3.
Y.
Shichi
,
S.
Tanimoto
,
T.
Goto
,
K.
Kuroiwa
, and
Y.
Tarui
,
Jpn. J. Appl. Phys., Part 1
33
,
5172
(
1994
).
4.
N.
Gong
and
T. P.
Ma
,
IEEE Electron Device Lett.
37
(
9
),
1123
1126
(
2016
).
5.
T. S.
Böscke
,
J.
Müller
,
D.
Bräuhaus
,
U.
Schröder
, and
U.
Böttger
,
Appl. Phys. Lett.
99
,
102903
(
2011
).
6.
T.
Shiraishi
,
K.
Katayama
,
T.
Yokouchi
,
T.
Shimizu
,
T.
Oikawa
,
O.
Sakata
,
H.
Uchida
,
Y.
Imai
,
T.
Kiguchi
,
T. J.
Konno
, and
H.
Funakubo
,
Appl. Phys. Lett.
108
,
262904
(
2016
).
7.
M. H.
Park
,
H. J.
Kim
,
Y. J.
Kim
,
T.
Moon
, and
C. S.
Hwang
,
Appl. Phys. Lett.
104
,
072901
(
2014
).
8.
U.
Schroeder
,
E.
Yurchuk
,
J.
Muller
,
D.
Martin
,
T.
Schenk
,
P.
Polakowski
,
C.
Adelmann
,
M. I.
Popovici
,
S. V.
Kalinin
, and
T.
Mikolajick
,
Jpn. J. Appl. Phys., Part 1
53
,
08LE02
(
2014
).
9.
P.
Polakowski
and
J.
Müller
,
Appl. Phys. Lett.
106
,
232905
(
2015
).
10.
X.
Sang
,
E. D.
Grimley
,
T.
Schenk
,
U.
Schroeder
, and
J. M.
LeBeau
,
Appl. Phys. Lett.
106
,
162905
(
2015
).
11.
M. H.
Park
,
H. J.
Kim
,
Y. J.
Kim
,
W.
Lee
,
T.
Moon
,
K. D.
Kim
, and
C. S.
Hwang
,
Appl. Phys. Lett.
105
,
072902
(
2014
).
12.
M. H.
Park
,
T.
Schenk
,
C. M.
Fancher
,
E. D.
Grimley
,
C.
Zhou
,
J. M.
LeBeau
,
J. L.
Jones
,
T.
Mikolajick
, and
U.
Schroeder
,
J. Mater. Chem. C
5
,
4677
4690
(
2017
).
13.
D.
Fischer
and
A.
Kersch
,
Appl. Phys. Lett.
92
,
012908
(
2008
).
14.
S.
Mueller
,
J.
Mueller
,
A.
Singh
,
S.
Riedel
,
J.
Sundqvist
,
U.
Schroeder
, and
T.
Mikolajick
,
Adv. Funct. Mater.
22
,
2412
2417
(
2012
).
15.
L.
Yao
,
X.
Liu
,
Y.
Cheng
, and
B.
Xiao
,
Nanotechnology.
32
,
215708
(
2021
).
16.
B.
Ku
,
S.
Choi
,
Y.
Song
, and
C.
Choi
, in
Symposium on VLSI Technology
(
IEEE
,
2022
).
17.
J.
Zhou
,
Z.
Zhou
,
X.
Wang
,
H.
Wang
,
C.
Sun
,
K.
Han
,
Y.
Kang
, and
X.
Gong
,
IEEE Electron Device Lett.
41
,
1130
1133
(
2020
).
18.
A. J.
Tan
,
Y.-H.
Liao
,
L.-C.
Wang
,
N.
Shanker
,
J.-H.
Bae
,
C.
Hu
, and
S.
Salahuddin
,
IEEE Electron Device Lett.
42
(
7
),
994
997
(
2021
).
19.
M. I.
Popovici
,
J.
Bizindavyi
,
P.
Favia
,
S.
Clima
,
M. N.
Alam
,
R. K.
Ramachandran
,
A. M.
Walke
,
U.
Celano
,
A.
Leonhardt
,
S.
Mukherjee
,
O.
Richard
,
A.
Illiberi
,
M.
Givens
,
R.
Delhougne
,
J.
Van Houdt
, and
G. S.
Kar
, in
IEEE International Electron Devices Meeting
(
IEEE
,
2022
).
20.
K. A.
Aabrar
,
S. G.
Kirtania
,
F.-X.
Liang
,
J.
Gomez
,
M. S.
Jose
,
Y.
Luo
,
H.
Ye
,
S.
Dutta
,
P. G.
Ravikumar
,
P. V.
Ravindran
,
A. I.
Khan
,
S.
Yu
, and
S.
Datta
,
IEEE Trans. Electron Devices
69
(
4
),
2094
(
2022
).
21.
W. C.
Chen
,
Y. C.
Zhang
,
P. H.
Chen
,
Y. T.
Tseng
,
C. H.
Wu
,
C. C.
Yang
,
P. Y.
Wu
,
Y. F.
Tan
,
S. K.
Lin
,
W. C.
Huang
,
H. C.
Huang
,
T. M.
Tsai
, and
T. C.
Chang
,
J. Phys. D: Appl. Phys.
53
,
445110
(
2020
).
22.
C. K.
Lee
,
E.
Cho
,
H. S.
Lee
,
C. S.
Hwang
, and
S.
Han
,
Phys. Rev. B
78
,
012102
(
2008
).
23.
P.
Ma
,
J.
Sun
,
G.
Zhang
,
G.
Liang
,
Q.
Xin
,
Y.
Li
, and
A.
Song
,
J. Alloys Compd.
792
,
543
549
(
2019
).
24.
M.
Kobayashi
,
J.
Wu
,
Y.
Sawabe
,
S.
Takuya
, and
T.
Hiramoto
,
Nano Convergence
9
,
50
(
2022
).
25.
J.
Müller
,
T. S.
Böscke
,
S.
Müller
,
E.
Yurchuk
,
P.
Polakowski
,
J.
Paul
,
D.
Martin
,
T.
Schenk
,
K.
Khullar
,
A.
Kersch
,
W.
Weinreich
,
S.
Riedel
,
K.
Seidel
,
A.
Kumar
,
T. M.
Arruda
,
S. V.
Kalinin
,
T.
Schlösser
,
R.
Boschke
,
R.
van Bentum
,
U.
Schröder
, and
T.
Mikolajick
, in
IEEE International Electron Device Meeting
(
IEEE
,
2013
), pp.
10.8.1
10.8.4
.
26.
M.
Pešić
,
F. P. G.
Fengler
,
L.
Larcher
,
A.
Padovani
,
T.
Schenk
,
E. D.
Grimley
,
X.
Sang
,
J. M.
LeBeau
,
S.
Slesazeck
,
U.
Schroeder
, and
T.
Mikolajick
,
Adv. Funct. Mater.
26
,
4601
4612
(
2016
).
27.
K. M.
Rabe
,
M.
Dawber
,
C.
Lichtensteiger
,
C. H.
Ahn
, and
J. M.
Triscone
,
Modern Physics of Ferroelectrics: Essential Background
(
Springer Berlin Heidelberg
,
2007
), pp.
1
30
.
28.
S.
De
,
B.-H.
Qiu
,
W.-X.
B
,
M. A.
Baig
,
P.-J.
Sung
,
C.-J.
Su
,
Y.-J.
Lee
, and
D.
Lu
,
ACS Appl. Electron. Mater.
3
,
619
628
(
2021
).
29.
L.
Collins
and
U.
Celano
,
ACS Appl. Mater. Interfaces
12
,
41659
41665
(
2020
).
30.
K. Y.
Chen
,
K. L.
Chu
,
P. H.
Chen
, and
Y. H.
Wu
,
RSC Adv.
6
(
78
),
74445
(
2016
).
31.
W. C.
Yap
,
H.
Jiang
,
J.
Liu
,
Q.
Xia
, and
W.
Zhu
,
Appl. Phys. Lett.
111
,
013103
(
2017
).
32.
J. L.
Eschle
and
S.
Kurinec
,
J. Microelectron. Eng. Conf.
24
(
1
),
19
(
2018
).
33.
T.
Srimani
,
G.
Hills
,
M. D.
Bishop
,
U.
Radhakrishna
,
A.
Zubair
,
R. S.
Park
,
Y.
Stein
,
T.
Palacios
,
D.
Antoniadis
, and
M. M.
Shulaker
,
IEEE Electron Device Lett.
39
,
304
307
(
2018
).
34.
C. C.
Fan
,
C. H.
Cheng
,
Y. R.
Chen
,
C.
Liu
, and
C. Y.
Chang
, in
IEEE International Electron Devices Meeting
(
IEEE
,
2017
), p.
23-2
.
35.
A.
Nourvakhsh
,
A.
Zubair
,
S.
Joglekar
,
M.
Dresselhaus
, and
T.
Palacios
,
Nanoscale
9
,
6122
6127
(
2017
).
36.
K.
Florent
,
S.
Lavizzari
,
L.
Di Piazza
,
M.
Popovici
,
E.
Vecchio
,
G.
Potoms
,
G.
Groeseneken
, and
J.
Van Houdt
, in
Symposium on VLSI Technology
(
IEEE
,
2017
), pp.
T158
T159
.
37.
H.
Ryu
,
K.
Xu
,
J.
Kim
,
S.
Kang
,
J.
Guo
, and
W.
Zhu
,
IEEE Trans. Electron Devices
66
(
5
),
2359
2364
(
2019
).
You do not currently have access to this content.