PZT (52/48)U c lT c l8 ý İ Ç% iP Æ X Øy ¢; c  \ ¥ º, P ê s ¥ ¹ Å ¤V R Ë õ m Í ÿ Ò Þy ¢8 ý ì Å× D
b 9 Ú . >
7 á ¤ ' a ¦1 p x < Æ § ² D G ] jì ø Í, S $ í 225-823
) ç * > · ¢ 9" k ∗
"
fy © @ / < Æ § Ó ü t o < Æõ , " fÖ ¦ 100-611 (2008¸ 10 Z 4 7{ 9 ~ Ã Î6 £ §)
_ "
t-7 q (sol-gel)~ ½ ÓZ O Ü ¼ Ð Pt (111)/Ti/SiO
2/Si l ó ø Í 0 A\ PbZr
0.52/Ti
0.48O
3~ Ã Ì} ` ¦ ] j # Ê ê\ P
%
o (post annealing)_ : r ¸ s § 4 / B G x 9 f . Ë (hall) 0 l x ¸\ p u H % ò ¾ Ó` ¦ ì r$ 3 % i . " l oÛ ¼Y Us
r] X (x-ray diffraction) θ − 2θ 8 £ ¤& ñ õ ¸ H ~ Ã Ì} É r @ /^ & h Ü ¼ Ð (100)õ (111) Ð Ä º $ í © % i 6 £ §
`
¦ S X Ù þ ¡Ü ¼ 9, \ V © õ H Ø Ô> 650
◦C \ " f Ê ê\ P % o ô Ç ~ Ã Ì} _ ï ß À Ó ì rF G ° ú כ (P
r) s 40 µC/cm
2s
© Ü ¼ Ð © ( H X <, s H (100) õ (111) " l oÛ ¼Y Us 4 x Ä ºo _ y © ¸ © H כ Ü ¼ ÐÂ Ò' & ñ $ í s ¾ Ó
© ) a כ Ü ¼ Ð s K ½ + É Ã º e % 3 . ¢ ¸ô Ç, Ê ê\ P % o : r ¸ 7 £ x " f ½ Ó > (E
c) ° ú כ ¸ 85 kV/cm Ð 7 £ x
ô Ç כ É r (100) õ (200) 4 x Ä ºo _ y © ¸ ¢ ¸ô Ç & t " f ½ ¨% i (domain)_ ì ø Í \ % ò ¾ Ó` ¦ p 2 ; כ Ü ¼ Ð s
K ½ + É Ã º e % 3 . ì rF G ° ú כõ H @ / ¸& h Ü ¼ Ð © Z } É r Ê ê\ P % o : r ¸ 675
◦C \ " f % o ô Ç ~ Ã Ì} É r
© Z } É r » ¡ ¤ 6 x | ¾ Ó` ¦ ? /% 3 H X <, PZT\ ¦ ì ø Í ¸^ Ð ç ß Å Ò # C - V~ ½ ÓZ O Ü ¼ Ð S X ô Ç f . Ë 0 l x ¸ H 1.9
× 10
14> h & ñ ¸ Ð © É r כ Ü ¼ Ð Ð Z } É r Ê ê\ P % o : r ¸\ _ ô Ç ± ú (Pb) o _ 7 £ x \ É r f .
Ë 0 l x ¸_ 7 £ x Ð H PZT _ Ä » : £ ¤$ í _ 7 £ x Å Ò כ ¹ s % 3 H z ´` ¦ · ú Ã º e % 3 .
PACS numbers: 77.80.-e, 77.84.-s
Keywords: y © Ä » $ í , y © Ä » ~ Ã Ì} , PZT, PbZr
0.52Ti
0.48O
3, f . Ë 0 l x ¸, _ " t-7 q
I. " e  ] Ø
y
© Ä » ^ F « Ñ[ þ t É r y © Ä » : £ ¤$ í ÷ r ë ß m · ú $ í (piezoelectricity), í l $ í (pyroelectricity), l F g < Æ (electro-optic) x 9 q + þ A F g < Æ (non-linear optic) : £ ¤$ í ` ¦
° ú
¦ e # Q ª ô Ç l 0 p x$ í è Ð_ 6 £ x6 x s 0 p x . s
Qô Ç y © Ä » ^ F « Ñ[ þ t × æ : £ ¤ y ± ú > \ P y © Ä » ^ o½ + ËÓ ü t
É
r Y > K Â Ò' r ' ÷ & H Ä »X O _ q ¨ 8 â 2 ; o& h Ó ü t| 9 _ ]
jô Ç\ ¸ Ô ¦ ½ ¨ ¦ Õ ª Ä ºÃ ºô Ç : £ ¤$ í Ü ¼ Ð K & ³r & h \ " f
¸ ´ ú § É r ½ ¨ü < 6 £ x6 x s s À Ò# Qt ¦ e . @ /³ ð& h ± ú >
\ P
Ó ü t| 9 × æ ` ÐÚ ÔÛ ¼ s à Ô (perovskite) ½ ¨ ¸\ ¦ t H PbZr
1−x,Ti
xO
3Ó ü t| 9 É r Ä ºÃ ºô Ç · ú $ í , í l $ í Ü ¼ Ð K
³ ð ò ø Í$ í 9 ' (surface acoustic wave filters), q \ P
o & h ü @ Ã Ðt l (uncooled infrared detectors) Õ ªo ¦ MEMS (micro-electromechanical system) l Õ ü t Ð 6 £ x6 x s 7
£
x @ /÷ & ¦ e . ¢ ¸ô Ç Z } É r ï ß À Óì rF G (remanent polariza- tion), ± ú É r ½ Ó l © (coercive field) Õ ªo ¦ ± ú É r ¾ º[ O
∗
E-mail: [email protected]
À
Ó (leakage-current)\ ¦ í < Ê H Ä ºÃ ºô Ç y © Ä » $ í M :ë H
\
q 6 fµ 1 Ï$ í B j ¸o (non-volatile RAM)_ 6 £ x6 x \ ¸ Ö ¸ µ
1 Ïy 6 x ÷ & ¦ e [1].
y
© Ä » ~ Ã Ì} É r Å Ò Ð PLDZ O , Û ¼( ' a AZ O , MOCVDZ O Õ
ªo ¦ _ " t- 0 q Z O 1 p x` ¦ s 6 x K ´ ú § É r ½ ¨Õ ªÒ ¨[ þ t s ] j K M
®
o [2–8]. ª ô Ç 7 £ x Ã Ì ~ ½ ÓZ O [ þ t É r ~ à Ì} _ ½ ¨ ¸, $ í © ~ ½ Ó
¾ Ó x 9 F G õ ~ Ã Ì} _ > : £ ¤$ í 1 p x \ H % ò ¾ Ó` ¦ p u >
÷
& 9 s : £ ¤$ í [ þ t É r y © Ä » : £ ¤$ í \ H % ò ¾ Ó` ¦ Å Ò H כ Ü ¼ Ð
· ú
94 R e . s × æ _ " t-7 q Z O É r { 9 ì ø Í& h Ü ¼ Ð \ P % o : r ¸
± ú ¦, $ í ì r q Ö ¦` ¦ © @ /& h Ü ¼ Ð 6 x s > ¸] X ½ + É Ã º e Ü
¼ 9, V , É r & h \ _ 7 £ x à Ìs 0 p x ¦ $ § 4 ô Ç q 6 x õ ç ß é
ß ô Ç / B N& ñ Ü ¼ Ð ´ ú § É r í ß \ O ^ ü < ½ ¨Õ ªÒ ¨ \ " f V , o 6 x
H 7 £ x Ã Ì ~ ½ ÓZ O s .
: r ½ ¨\ " f À Ò H PZT (PbZr
1−x,Ti
xO
3) H Zr õ Ti _ © @ / q Ö ¦ \ Õ ª : £ ¤$ í _ s ¿ º× ¼ Qt H X
< : £ ¤ y , Zr : Ti=1:1 (7 £ ¤, x = 0.5) H % q Ö ¦ É r Mor- photropic Phase Boundary (MPB) Ð · ú 94 R e Ü ¼ 9 & ñ
~
½ Ó& ñ > (tetragonal)ü < ~ ½ Ó& ñ > (rhombohedral)_ © [ þ t s
D ¥ F H % ò % i Ü ¼ Ð · ú 94 R e [9]. : £ ¤ y , [ j b _
-347-
â
Ä º MPB H ~ ½ Ó% ò % i \ " f © @ / Ä » Ö ¦ õ l % i < Æ& h
½
+ Ë © Ã º þ j@ /° ú כ` ¦ ° ú l M :ë H \ · ú $ í x 9 y © Ä » $ í : £ ¤
$ í
\ ' a ô Ç ½ ¨ | 9 × æ& h Ü ¼ Ð s À Ò# Q4 R M ® o [10]. þ j H
\
H B j ¸o _ Z } É r | 9 & h Ö ¦` ¦ 0 A # ~ Ã Ì} _ ¿ ºa & h
&
h · û ª t " f ~ Ã Ì} _ e > ¿ ºa x 9 > : £ ¤$ í \ ' a ô Ç
½
¨ Ö ¸ µ 1 Ïy ' ÷ & ¦ e . : £ ¤ y " l oÛ ¼ í ß ê ø Í [11], ¦ ì
r K 0 p x È Òõ & ³p â [12]1 p x` ¦ s 6 x ô Ç ½ ¨ s ü @\
¸ l & h : £ ¤$ í ` ¦ ì r$ 3 H ~ ½ ÓZ O s e H X <, Å Ò Ð P - E, C - V ü < I - V1 p x s @ /³ ð& h s . þ j H \ s Qô Ç 8 £ ¤& ñ
~
½ ÓZ O [ þ t (» ¡ ¤ 6 x | ¾ Ó, À Óx 9 ¸ 1 p x)` ¦ : x # y © Ä » ~ Ã Ì} _
Ó ü t o & h & ³ © (: £ ¤ y , Ã º5 Å x x 9 Ä » : £ ¤$ í )` ¦ s K
¦ ½ + É M : y © Ä » ^ \ ¦ Ä » ^ Ð s K t · ú § ¦ H ½
×
¼ Ì s ` ¦ t H ì ø Í ¸^ Ð s K # ª ô Ç Ó ü t o & h & ³ ©
`
¦ s K 9 H r ¸ e . @ /³ ð& h Ü ¼ Ð À Óx 9 ¸\ ¦
½ ÓÜ ¼ Ð y © Ä » ~ Ã Ì} _ : £ ¤$ í ` ¦ s K ¦ H â Ä º\
HSchottky emission, Fowler Nordheim tunneling, space charge limited ü < Pool-Frenkel emission1 p x _ B j& m 7 £ §[ þ t s
s 6 x ÷ & H X <, > : £ ¤$ í \ _ K " f s 1 l x s & ñ ÷ &
H â Ä º\ y © Ä » ^ Ä » ^ (< Ê É r Â Ò ¸^ ) t ì ø Í ¸^
t \ ¦ ½ ¨Z > H כ É r Ä »´ ò l © _ > í ß \ e # Q" f
© × æ כ ¹ô Ç כ ¹ Ü ¼ Ð · ú 94 R e [13, 14]. ÷ r ë ß m C - V/ B G ` ¦ s 6 x H â Ä º\ ¸ » ¡ ¤ 6 x | ¾ Ó_ o_ " é ¶
Ü ¼ Ð l © _ o\ _ ô Ç Ä » © Ã º_ o Ð s K
½
+ É כ t , F K5 Å q F G õ y © Ä » ~ Ã Ì} s \ " f µ 1 ÏÒ q t H /
B N 9 8 £ x (depletion layer) _ o Ð s K ½ + É t \ ¦ & ñ K
l M :ë H \ Ä » ^ ü < ì ø Í ¸^ \ ¦ " î S X > ½ ¨Z > K ô
Ç [15]. s Qô Ç Ó ü t o & h כ ¹½ ¨ Ð # , : r ½ ¨\ " f H _
"
t-7 q Z O Ü ¼ Ð 7 £ x à Ìô Ç PbZr
0.52Ti
0.48O
3_ Ê ê\ P % o : r ¸
\
É r ~ Ã Ì} _ ½ ¨ ¸_ o\ ¦ ' a ¹ 1 Ï ¦ @ /³ ð& h y © Ä »
^ _ : £ ¤$ í P - V ü < ì ø Í ¸^ : £ ¤$ í ` ¦ · ú Ã º e H f . Ë 0 l x
¸_ o\ ¦ ' a ¹ 1 Ï # q §K Ð ¦ ô Ç .
II. ÷ m Ç ] M ö
Pb 10 % íõ ) a PbZr
0.52Ti
0.48O
36 xÓ o` ¦ { 9 : r _ KOJUNDO o < Æ\ " f ½ ¨B % i Ü ¼ 9, l ó ø Í É r Ti/SiO
2/Si 0
A\ (111)~ ½ Ó ¾ ÓÜ ¼ Ð ¸ ú & ñ o ) a Pt\ ¦ 6 x % i . 6 xÓ o
`
¦ Pt l ó ø Í 0 A\ Û ¼ ís × ¼\ ¦ s 6 x # ¸ íô Ç Ê ê 3000 rpm Ü ¼ Ð 30 íç ß Û ¼ 2 ; ïh A` ¦ ô Ç . ïh A ) a ~ Ã Ì} É r 200
◦
C _ \ P ó ø Í (hot plate) 0 A\ " f 1ì r 1 l x î ß | ¸ ¦ 400
◦
C _ \ P ó ø Í 0 A\ " f 5ì r 1 l x î ß \ P ì r K (pyrolysis) õ & ñ ` ¦
2 ; . y © Ä » : £ ¤$ í ` ¦ S X Ð l 0 A # s ü < ° ú É r õ
&
ñ ` ¦ 4 r ì ø Í4 ¤ % i Ü ¼ 9, þ j7 á x ïh A` ¦ ¢ - a « Ñô Ç Ê ê : r ¸\ ¦ 575
◦C \ " f 675
◦C t 25
◦C ç ß Ü ¼ Ð ¸] X # / B N
Fig. 1. X-ray diffraction patterns of PZT(52/48)/Pt/
Ti/SiO
2/Si thin films annealed at the ranges from 575
◦
C to 675
◦C. •, and shows (100), (111) and (200) Bragg peaks, respectively.
l
ì r 0 Al _ tube furnace\ " f 5ì r 1 l x î ß Ê ê\ P % o ô Ç .
~ Ã
Ì} _ ¿ ºa H 200nm H d` ¦ Field Emission Scan- ning Electron Microscope (FE-SEM) õ " é ¶¼ # F gì r$ 3 l (ellipsometry)\ ¦ : x # S X % i .
~ Ã
Ì} _ ½ ¨ ¸\ ¦ S X l 0 A # " l oÛ ¼Y Us r] X © u (Bruker axs D8 discover)\ ¦ s 6 x # θ−2θ scan` ¦ 0.002
◦ç
ß Ü ¼ Ð z ´r % i Ü ¼ 9, ª ô Ç l & h : £ ¤$ í ` ¦ S X l 0
AK 6.0 × 10
−6torr _ / B Nì r 0 Al \ " f \ P 7 £ x Ã Ì (thermal evaporation) ~ ½ ÓZ O Ü ¼ Ð t 2 £ § 140 µm _ " é ¶+ þ A_ F K (Au) Ü ¼
Ð ) a © Â Ò F G` ¦ ] j % i .
ì
rF G ° ú כ` ¦ S X l 0 AK Radiant _ RT66A\ ¦ s 6 x
# virtual ground ~ ½ ÓZ O Ü ¼ Ð P - V s § 4 / B G ` ¦ 8 £ ¤& ñ
%
i ¦, e x ~ Û ¼ ì r$ 3 l (impedance analyzer) HP4194A
\
¦ s 6 x # C - V / B G ` ¦ 8 £ ¤& ñ % i . C - V/ B G ` ¦ 8 £ ¤
&
ñ ½ + É M :\ H 1 l xï r 0 A (oscillation level)\ ¦ 0.10 V Ð
#
Ò re ¦a A l © s y © Ä » : £ ¤$ í (: £ ¤ y , ì rF G ° ú כ)\ p u
H % ò ¾ Ó` ¦ þ j è o % i .
III. ÷ m Ç] M ö+ s ÇÊ Ý õ m Í w ² o
~ Ã
Ì} _ ¿ ºa H 200 nme ` ¦ FE-SEM õ " é ¶¼ # F gì r
$
3 l \ ¦ s 6 x # S X % i . Fig. 1 É r ~ Ã Ì} [ þ t _ Ê ê\ P
%
o : r ¸\ É r " l oÛ ¼Y Us r] X õ s . ¸ H ~ Ã Ì} s
(100)/ (200)õ (111)Ü ¼ Ð Ä º $ í © % i Ü ¼ 9 Õ ª ü @_
& ñ ~ ½ Ó ¾ Ó É r ¹ 1 Ô ^ ¦ Ã º \ O % 3 . s Qô Ç z ´ ÐÂ Ò' q
§& h & ñ | 9 s Ä ºÃ ºô Ç ~ à Ì} s + þ A$ í ÷ &% 3 6 £ §` ¦ · ú à º e % 3
. & ñ o : r ¸ q §& h ± ú É r 525
◦C ü < 550
◦C _ ~ Ã Ì}
Fig. 2. P - E hysteresis loops of the thin films annealed at the ranges from 600
◦C to 675
◦C. The sampling fre- quency and voltage are 500 Hz and 7 V, respectively.
`
¦ ] jü @ ¦ 552 cm
−1õ 594 cm
−1ë ß 4 x Ä ºo 1 l x r
\ ' a8 £ ¤ ÷ &# Q & ñ S X > ~ ½ Ó& ñ > _ @ /g A$ í ` ¦ ° ú > H d
`
¦ · ú Ã º e % 3 ¦ [16], ï r î ß & ñ © (metastable phase) pyrochlore ü < ' aº ) a ( Å Ò Ð Pb
2Ti
2O
6) 750 cm
−1Â Ò H _
ë ß 4 x Ä ºo ' a8 £ ¤ ÷ &t · ú § É r כ Ü ¼ Ð Ð & ñ | 9 _ Ä º Ã
º$ í ` ¦ · ú Ã º e % 3 [17]. Ê ê\ P % o : r ¸ 7 £ x ½ + ÉÃ º2 ¤ (100)/ (200) õ (111) 4 x Ä ºo _ y © ¸ 7 £ x % i H X <, : £ ¤ y
650
◦C \ " f Ê ê\ P % o ô Ç ~ Ã Ì} \ " f © H ° ú כ` ¦
Ê ê 675
◦C \ " f p [ j > × ¦ # Q[ þ U` ¦ S X ½ + É Ã º e % 3 .
7 á
§ 8 [ jy ¶ ú ( R Ð 575
◦C ü < 600
◦C \ " f Ê ê\ P % o ô
Ç ~ Ã Ì} _ peak_ y © ¸ H Ð Z } É r : r ¸\ " f Ê ê\ P % o
ô Ç ~ Ã Ì} [ þ t \ q K 6 £ §` ¦ · ú Ã º e . : £ ¤ y (200) Â Ò
H _ peak É r (002) ü < (200)Ü ¼ Ð ì r o ÷ &# Q e % 3 H X <, ©
@
/& h Ü ¼ Ð ± ú É r : r ¸\ " f Ê ê\ P % o ô Ç ~ Ã Ì} _ â Ä º z · ú (grain) _ Ù þ + þ A$ í s ¸ ú ' ÷ &t 3 l w ¦ aü < c» ¡ ¤ ~ ½ Ó ¾ ÓÜ ¼
Ð z · ú s D ¥ F ÷ &# Q e 6 £ §` ¦ · ú 9Å Ò H õ s . aü < c» ¡ ¤ Ü
¼ Ð $ í © ô Ç z · ú s 1 l x r \ Ò q tl H כ É r © @ /& h Ü ¼ Ð ± ú
É
r : r ¸ (150
◦C) \ " f \ P ì r K ½ + É â Ä º\ ¸ z ¤ H X <, (100) õ (001)_ 4 x Ä ºo Z } É r : r ¸\ " f \ P ì r K % i ` ¦ M
: Ð Ì º§  > ì r o ÷ & ¦ e 6 £ §` ¦ · ú à º e % 3 . : £ ¤ y ,
 Ò8 £ x ( > õ î r 8 £ x) õ ©  Ò8 £ x ( ³ ð õ î r 8 £ x) _
x 9 ¸ (e/˚ A
3) ü < tetragonality (c/a ratio) 2 £ §` ¦
"
l oÛ ¼Y Us ì ø Í Ö ¦ 8 £ ¤& ñ ` ¦ : x # S X % i [18]. s Q ô
Ç z ´` ¦ ½ ÓÜ ¼ Ð © @ /& h Ü ¼ Ð Z } É r : r ¸\ " f_ íl
|
¸ ¸ Ê ê\ P % o : r ¸ ± ú É r â Ä º\ H a ü < c» ¡ ¤ Ü ¼ Ð
½
¨% i s 1 l x r \ µ 1 ÏÒ q t½ + É Ã º e 6 £ §` ¦ · ú Ã º e % 3 . s Qô Ç
\ P
ì r K : r ¸ü < Ê ê\ P % o : r ¸ç ß _ © ñ Ð ¢ - a& h ' a > H Bi
4−xLa
xTi
3O
12~ Ã Ì} \ " f ¸ S X ½ + É Ã º e % 3 H X < [19], y © Ä
» ~ Ã Ì} ` ¦ a % ¦ - 0 q Z O Ü ¼ Ð ] j H â Ä º\ \ P ì r K : r
¸ü < Ê ê\ P % o : r ¸\ ¦ & ñ # z · ú _ ß ¼l x 9 ½ ¨% i _
¸ ª ` ¦ & ñ H X < × æ כ ¹ô Ç « Ñ | ¨ c כ Ü ¼ Ð Ò q ty ) a .
Fig. 3. C - V curves of the films annealed at the ranges from 600
◦C to 675
◦C. The highest capacitance is recorded for the film annealed at 675
◦C.
¢
¸ô Ç ~ Ã Ì} ] j r \ 200
◦C _ | ¸é ß > \ ¦ Ò q t| Ä Ì > ÷ &
(111) ~ ½ Ó ¾ ÓÜ ¼ Ðë ß $ í © > ÷ & 9 ½ Ó > ° ú כs ¦ ½ Ó
> Â Ò H \ " f_ dP/dE 8 p u` ¦ · ú Ã º e % 3 [20].
s
z ´ É r (111) ~ ½ Ó ¾ ÓÜ ¼ Ðë ß $ í © ô Ç ~ Ã Ì} _ ½ ¨% i ì ø Í s
(100)/ (001) ~ ½ Ó ¾ Óõ 8Ô ¦ # Q 4 ¤ ½ + Ë& h Ü ¼ Ð $ í © ô Ç ~ Ã Ì}
Ð 8 Ø Ô H z ´` ¦ · ú 9Å Ò H כ É r Ó ü t : r s ¦, $ í ©
~
½ Ó ¾ Óõ ½ ¨% i ì ø Í _ 5 Å q ¸\ ¦ ¸] X ô Ç PZT ~ Ã Ì} _ ] j s sol-gel Z O Ü ¼ Ð 0 p x < Ê` ¦ r ô Ç . Fig. 2 H 600
◦C \ " f 675
◦C t Ê ê\ P % o ô Ç ~ Ã Ì} [ þ t _ P -V / B G s .
ô
Ç ` O Û ¼_ Å Ò Ã º H 500 Hz s ¦ s M : · ú É r 7 V s .
Õ
ªa Ë >\ " f ^ ¦ Ã º e H כ % ! 3 © @ /& h Ü ¼ Ð ± ú É r : r ¸\ " f Ê
ê\ P % o ô Ç ~ Ã Ì} É r / B G s ¸ ú í o÷ &t 3 l w ¦ 1 l x r \ ï
ß À Óì rF G ° ú כs ¦ ½ Ó > ° ú כs ( . " l oÛ ¼Y Us r] X õ \ _ ô Ç peak_ y © ¸\ ¦ : x # ~ 1 > \ V © ½ + É Ã º e % 3
~
כ % ! 3 , 650
◦C \ " f Ê ê\ P % o ô Ç ~ Ã Ì} _ ì rF G ° ú כs
© ( t ë ß ½ Ó > ° ú כ É r 675
◦C Ð ( . s Qô Ç z ´ É r
"
l oÛ ¼Y Us r] X ì r$ 3 ` ¦ : x K " f (200) ~ ½ Ó ¾ Ó_ z · ú (a» ¡ ¤) s 675
◦C Ð ´ ú § כ Ü ¼ РÒ' ~ 1 > Ä »Æ Ò½ + É Ã º e % 3 .
Fig. 3 É r 600
◦C \ " f 675
◦C t Ê ê\ P % o ô Ç ~ Ã Ì} [ þ t
\
@ /K 10 kHz\ " f 8 £ ¤& ñ ô Ç C - V / B G s . / B G É r { 9 ì
ø Í& h y © Ä » ~ Ã Ì} \ " f ^ ¦ Ã º e H q ¸ ª s % 3 Ü ¼ 9, Õ
ªa Ë >\ " f S X ½ + É Ã º e H כ õ ° ú s » ¡ ¤ 6 x | ¾ Ós © H
· ú ( Ð: x É r P - E _ ½ Ó > ° ú כ H % Ð s K ô Ç .)_ ß ¼ l
Ê ê\ P % o : r ¸ 7 £ x ½ + ÉÃ º2 ¤ × ¦ # Q[ þ U` ¦ · ú Ã º e % 3
. s ü @\ ¸ 1 kHz, 100 kHz, 1 MHz_ Ò re ¦a A Å Ò Ã º
\
¸ q 5 p w ô Ç â ¾ Ós ' a ¹ 1 Ï÷ &% 3 . t ë ß Õ ªa Ë >\ " f ¸ @ /
| Ä
Ì& h Ü ¼ Ð ' a ¹ 1 Ͻ + É Ã º e H כ % ! 3 dC/dV H + þ A& h
o\ ¦ ° ú t 3 l w ¦ e . s Qô Ç z ´ É r { 9 ì ø Í& h ì ø Í ¸^
Shottky ] X ½ + Ë (Shottky contact)s : r` ¦ & h 6 x # ½ ¨ô Ç f . Ë
0 l
x ¸_ o\ ¦ \ V8 £ ¤ ½ + É M : × æ כ ¹ô Ç כ ¹ è ) a . = f
. Ë 0 l x ¸ (N
dop) H
N
dop= 2
qε
0ε
ST[(d(1/C
2/dV ))]
Ð & ñ _ | ¨ c à º e H X < [21], # l " f ε
0ü < ε
ST H y y / B N õ Ä
» ^ _ Ä » Ö ¦ s . s M : Ä » Ø Ô> h (free carrier)ë ß s
É r Ò re ¦a A Å Ò Ã º\ ì ø Í6 £ x ¦ / B N 9 % ò % i (depleted region) î ß _ · ¡ ~ Ã Ìs (fixed charge)_ â Ä º H ì ø Í6 £ x
t · ú § H . Õ ªX O l M :ë H \ Ô ¦í HÓ ü t (dopant) _ 7 á x À Ó\ ¦
· ú
¦ e C - V\ ¦ 8 £ ¤& ñ # f . Ë 0 l x ¸\ ¦ ½ ¨½ + É Ã º e .
s
M : W = x 9 ¸ (trap density)_ ´ òõ Á ºr ½ + É Ã º e ` ¦ & ñ
¸ Ð ë ß í H à ºô Ç ¸i ç 0 l x ¸\ ¦ ½ ¨½ + É Ã º e H X <, : £ ¤ y
í H Ã º > ¸i ç 0 l x ¸\ ¦ S X l 0 AK " f H \ P ~ ½ ÓØ ¦Ò ¦ (e − n, thermal emission rate) s Å Ò# Q : r ¸\ " f Á ºr
| ¨
c à º e # Q ¦ Ò re ¦a A Å Ò Ã º Ð ¸ s ` ô Ç
[17]. s Qô Ç ¸| ` ¦ ë ß 7 á ¤ ô Ç C - V\ ¦ : x K " f S \ 1
p
q ô Ç N
dop H Ä » Ø Ô> h 0 l x ¸ (free carrier concentra- tion) ) a . Fig. 3_ C - V/ B G [ þ t` ¦ l : r Ü ¼ Ð 0 A_ d
`
¦ & h 6 x # ½ ¨ô Ç õ Fig. 4\ e . Õ ªa Ë >\
"
f ^ ¦ Ã º e H כ % ! 3 f . Ë 0 l x ¸ H 1.9 × 10
14/cm
3\ " f 1.3
× 10
15/cm
3Ü ¼ Ð ô Ç · ú \ " f ^ & h Ü ¼ Ð { 9 & ñ >
z ¤ . < É ª p Ðî r כ É r \ P % o : r ¸ 7 £ x ½ + ÉÃ º2 ¤ 6 f µ
1 Ï ) a Pb _ ª s ´ ú § " f f . Ë 0 l x ¸ 7 £ x ½ + É כ Ü ¼ Ð \ V ©
÷
&% 3 t ë ß 625
◦C ü < 650
◦C s \ " fë ß + þ A& h ' a >
Ðs ¦ 575
◦C ü < 675
◦C \ " f H & ñ ì ø Í@ /_ õ \ ¦ ' a ¹ 1 Ï
½
+ É Ã º e % 3 . Ê ê\ P % o : r ¸\ " f U · É r ï r 0 A (deep level) _ ´ òõ \ ¦ Ã º e 6 £ §` ¦ S X l 0 A # Ò re ¦ a A Å Ò Ã º\ ¦ 1 kHz, 100 kHz, 1 MHz Ð ª > ¸& ñ
#
8 £ ¤& ñ ô Ç C - V ÐÂ Ò' S \ 1 p q ô Ç õ ¸ Ò re ¦ { © f . Ë 0 l x ¸ _
o H e % 3 t ë ß @ /^ & h Ü ¼ Ð q 5 p w ô Ç â ¾ Ó` ¦ & .
· ú
¡" f [ O " î ô Ç ü < ° ú s 575
◦C \ " f_ f . Ë 0 l x ¸ 1.3
× 10
15/cm
3Ü ¼ Ð © H ° ú כÜ ¼ Ð z ¤Ü ¼ 9, ô Ǽ # Ê ê\ P
%
o : r ¸ © Z } É r 675
◦C \ " f H © É r ° ú כ 1.9
× 10
14/cm Ü ¼ Ð z ¤ . s X O > © @ /& h Ü ¼ Ð ± ú Z }
É
r Ê ê\ P % o : r ¸\ " f q & ñ © & h f . Ë 0 l x ¸ ' a8 £ ¤ ) a כ
É
r ~ Ã Ì} _ ï ß À Ó 6 x B (residual solvent), z · ú â > (grain boundary) x 9 < Ê\ _ ô Ç · û É r ï r 0 A (shallow level) H
6 x` ¦ Ù þ ¡` ¦ כ s . 7 á § 8 [ jy ´ ú , 575
◦C \ " f Ê
ê\ P % o ô Ç ~ Ã Ì} _ â Ä º © @ /& h Ü ¼ Ð ¸ ú + þ A$ í ÷ &t 3 l w ô Ç z
· ú â > x 9 PZT é ß 0 A± ú ñ ß ( < Ê` ¦ í < Êô Ç)\ _ #
ª _ · û É r ~ Ã Î> h (shallow acceptor)\ _ ô Ç f . Ë 0 l x ¸
7 £ x Ù þ ¡` ¦ כ s ¦, ì ø Í@ / Ð 675
◦C \ " f Ê ê\ P % o ô Ç ~ Ã Ì }
_ â Ä º © @ /& h Ü ¼ Ð Z } É r : r ¸\ _ # > H % \
"
f µ 1 ÏÒ q tô Ç í ß è o (oxygen vacancy) Å Ò> h (donor)
Fig. 4. The hole concentrations calculated from the C- V curves are shown. The hole concentration is at the ranges from 1.9 × 10
14/cm
3to 1.3 × 10
15/cm
3, and that is almost constant at all applied biases.
+ þ
AI _ · û É r ï r 0 A x 9 U · É r ï r 0 A\ ¦ + þ A$ í % i ` ¦ כ Ü ¼ Ð ó ø Í é
ß ) a . s Qô Ç & ³ © _ " é ¶ ` ¦ Ð & ñ S X > S X l 0
AK " f H 1) < Ê_ Å Ò ) a " é ¶ ` ¦ # ¦ (Pb, Ti, O, Zr _ o < Æ& h ½ ¨$ í q Ö ¦` ¦ Angle Resolved Photo Emission Spectroscopy (ARPES) < Ê É r X-Ray specular Reflectivity (XRR)\ ¦ s 6 x # S X ½ + É Ã º e ` ¦ כ s [22,23].)
2) ' 0 l x ¸ (Doping concentration)\ U · É r ï r 0 A_ l
# H & ñ ¸\ ¦ l 0 A # : r ¸\ ¦ or v " f C-V\ ¦ S X K ô Ç . (U · É r ï r 0 A l # t · ú § H
: r ¸_ o\ Á º ' a ô Ç f . Ë 0 l x ¸ 8 £ ¤& ñ ÷ &# Q ô Ç [17].)
IV. + s Ç Â ] Ø
: r ½ ¨\ " f H PbZr
0.52/Ti
0.48O
3` ¦ Pt (111) l ó ø Í 0 A
\
_ " t - 0 q Z O Ü ¼ Ð 7 £ x Ã Ì ¦, Ê ê\ P % o : r ¸\ ¦ ¸] X #
½
¨ ¸, P - V, C - V x 9 f . Ë 0 l x ¸_ o\ ¦ ' a ¹ 1 Ï % i . ¸
H ~ Ã Ì} É r (100) õ (111) Ð $ í © % i Ü ¼ 9 650
◦C \ " f Ê ê
\ P
% o ô Ç ~ Ã Ì} _ " l oÛ ¼Y Us r] X 4 x Ä ºo _ [ jl © (
. s כ Ü ¼ ÐÂ Ò' ì rF G ° ú כs © H כ É r & ñ $ í \ l
% i 6 £ §` ¦ · ú Ã º e % 3 Ü ¼ 9, 1 l x r \ (100)Ü ¼ Ð $ í © ô Ç z
· ú
\ _ # ½ Ó > ° ú כ ¸ & t > H d` ¦ · ú Ã º e % 3 . s Q ô
Ç z ´[ þ t É r íl | ¸\ ¦ Ò q t| Ä Ì % i ` ¦ â Ä º (111) Ðë ß $ í
© ½ + É Ã º e H s ½ ¨ õ ü < 8Ô ¦ # Q" f ì rF G ° ú כõ ½ Ó
> ° ú כ` ¦ ¸] X ½ + É Ã º e H × æ כ ¹ô Ç t ³ ð | ¨ c à º e ` ¦ כ Ü
¼ Ð ó ø Íé ß ) a .
Shottky ] X 8 ú ¤ s : r` ¦ & h 6 x # % 3 É r f . Ë 0 l x ¸ H 1.9 ×
10
14/cm
3\ " f 1.3 × 10
15/cm
3Ü ¼ Ð ô Ç · ú \ " f { 9
&
ñ > z ¤Ü ¼ 9, \ V © õ H Ø Ô> Ê ê\ P % o : r ¸\
" f q Y V H f . Ë 0 l x ¸\ ¦ S X ½ + É Ã º \ O % 3 H X <, s H
Ä » Ø Ô> h 0 l x ¸ H Pb _ o ÷ r ë ß m , < Ê x 9 í
ß è o _ % ò ¾ Ó` ¦ ~ Ã Îl M :ë H s . : £ ¤ y , 575
◦C \ " f _
f . Ë 0 l x ¸ 1.3 × 10
15/cm
3Ü ¼ Ð © H ° ú כÜ ¼ Ð
z ¤Ü ¼ 9, ô Ǽ # Ê ê\ P % o : r ¸ © Z } É r 675
◦C \ " f H
© É r ° ú כ 1.9 × 10
14/cm Ü ¼ Ð z ¤ . s X O > ©
@
/& h Ü ¼ Ð ± ú Z } É r Ê ê\ P % o : r ¸\ " f q & ñ © & h f . Ë 0
l
x ¸ ' a8 £ ¤ ) a כ É r ~ Ã Ì} _ ï ß À Ó 6 x B (residual solvent), z
· ú â > (grain boundary) x 9 < Ê\ _ ô Ç · û É r ï r 0 A
H 6 x` ¦ Ù þ ¡` ¦ כ Ü ¼ Ð ó ø Íé ß ) a .
P
c p 8 ý ò k >
s
7 Hë H É r 2007¸ ¸ & ñ Â ÒF " é ¶ ( §¹ ¢ ¤ & h " é ¶ Â Ò < ÆÕ ü t
½ ¨ ¸$ í \ O q )Ü ¼ Ð ô Dz D G < ÆÕ ü t < É ª F é ß _ t " é ¶` ¦ ~ à Î
½ ¨÷ &% 3 6 £ § (KRF-2007-C00212-20073037).
Y
c p w à U Ø ô
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Changes in the Crystal Structure, the Ferroelectric Properties, and the hole Concentration for PZT (52/48) Thin Films as a Function of the
Annealing Temperature
Jeonho Jin
International Class, Korean Minjok Leadership Academy, Hoengseong 225-823
Sungmin Park and Gwangseo Park
∗Department of Physics, Sogang University, Seoul 100-611 (Received 7 October 2008)
We analyzed the effect of the post-annealing temperature on the hysteresis curves and the hole concentrations for PbZr
0.52/Ti
0.48O
3thin films deposited on Pt (111)/Ti/SiO
2/Si substrates by using a sol-gel method. We found that all films were predominantly (100) and (111) oriented.
Contrary to expectations, a remanent polarization value of 40 µC/cm
2was observed in the film annealed at 650
◦C, which is the highest one in the films. This is believed to have originated from an enhancement of the crystallization, which was verified by the intensities of both the (100) and the (111) X-ray peaks being highest. In addition, the fact that the coercive field increased as the annealing temperature was increased is due to the change in domain switching coming from the increases in the intensities of the (100) and the (200) X-ray peaks. Compared to the polarization value, the film annealed at 675
◦C had the highest value of the capacitance. Based on the lowest hole concentration of the films, which was about 1.9 × 10
14, evaluated from the C-V measurement with PZT being considered as semiconductor, we believe that the highest capacitance mainly arises from an enhancement of the dielectric properties of the PZT thin film, not from an increase in the hole concentration induced by an increase in the number of Pb vacancies at higher annealing temperatures.
PACS numbers: 77.80.-e, 77.84.-s
Keywords: Ferroelectricity, Ferroelectric thin film, PZT, PbZr
0.52Ti
0.48O
3, Hole concentration, Sol-gel
∗