½ ¨ 7 Hë H Sae Mulli (The Korean Physical Society), Volume 57, Number 4, 2008¸ 10 Z 4, pp. 287∼290
Si (111) M m ü; c V R ËX ê s X ¢ GaN «8 ý $ [Æ X Ø AlN ú n Þ m « ¤B s; c  \ ¥ ¤V R Ë
»% ¦ ∗
' õ
AÅ Ò@ / < Æ § & ñ Ð/ B N < ÆÂ Ò, ' õ AÅ Ò 360-746 (2008¸ 7 Z 4 31{ 9 ~ Ã Î6 £ §)
Ä
»l o < Æl © 7 £ x à ÌZ O Ü ¼ Ð $ : r AlN × æ ç ß 8 £ x` ¦ s 6 x # Si (111) l ó ø Í0 A\ GaN ~ à Ì} ` ¦ $ í © ¦
$
: r AlN × æ ç ß 8 £ x ¿ ºa \ É r : £ ¤$ í ` ¦ ½ ¨ % i . $ : r AlN × æ ç ß 8 £ x ¿ ºa \ GaN 8 £ x _ ç H\ P s
y > < Ê` ¦ · ú Ã º e % 3 ¦ 10 nm ¿ ºa \ " f ç H\ P x 9 ¸ 5/cm _ © & h É r ç H\ P ` ¦ % 3 % 3 . ¢ ¸ô Ç, (002) X-ray rocking curve _ full width at half maximum 8 £ ¤& ñ õ 651 arcsec _ & ñ $ í ` ¦ ° ú H ~ Ã Ì }
` ¦ % 3 % 3 ¦ photoluminescence 8 £ ¤& ñ õ 300 K \ " f 38.1 meV _ full width at half maximum ` ¦
% 3
% 3 .
PACS numbers: 68.55.-a, 62.20Mk, 81.40.Jj
Keywords: $ : r AlN × æ ç ß 8 £ x, ç H\ P , z ´o B H (111), Ä »l o < Æl © 7 £ x à Ì
I. " e  ] Ø
þ
j H \ , Si l ó ø Í É r $ o, @ /6 x | ¾ Ó o, Õ ªo ¦ a % ~ É r \ P x 9
l & h ¸$ í 1 p x _ © & h M :ë H \ GaN_ $ í © l ó ø ÍÜ ¼
Ð ´ ú § É r ' a d ` ¦ ~ Ã Î ¸ ¦ e . t ë ß , GaNü < Si l ó ø Í
s _ H © Ã º Ô ¦{ 9 u ü < \ P Ø ½ Ó > Ã º_ s Ð K
µ 1 ÏÒ q t H GaN ç H\ P (crack) s Si l ó ø Í` ¦ s 6 x ô Ç GaN _
$ í © \ a Ë >[ t ÷ & ¦ e . ´ ú § É r ½ ¨ [ þ t É r Si l ó ø Í\
"
f # Q t ! Q( 8 £ x (buffer layer)` ¦ 6 x # ¦¾ ¡ §| 9 , Á
ºç H\ P GaN \ ¦ % 3 l 0 AK ¸§ 4 % i Ü ¼ , 1 µms © _ Á º ç
H\ P (crack-free) GaN $ í © l ' p é ß { 9 ! Q( 8 £ x ë ß Ü ¼ Ð H ô
Ç> e % 3 . s ü < ° ú É r s Ä » Ð × æ ç ß 8 £ x (interlayer) ` ¦
¶ ú
{ 9 H ~ ½ ÓZ O s ¸{ 9 ÷ &% 3 ¦ × æ ç ß 8 £ x Ü ¼ Ð $ : r AlN [1], SiNx [2], Õ ªo ¦ × æ8 £ x (multilayer) [3] 1 p x` ¦ s 6 x H
½ ¨ ' ÷ & ¦ e . Õ ª × æ \ " f ¸ $ : r AlN × æ ç ß 8 £ x` ¦ s
6 x ô Ç $ í © Z O É r ç ß é ß " f & ñ < Ê (defect) õ ç H\ P
`
¦ 1 l x r \ × ¦{ 9 Ã º e H $ í © Z O Ü ¼ Ð · ú 94 R e . Õ ª Q
, a % ~ É r : £ ¤$ í ` ¦ ° ú H $ í © Z O e \ ¸ Ô ¦ ½ ¨ ¦ $ : r AlN
×
æ ç ß 8 £ x $ í © Z O \ @ /ô Ç ½ ¨ H f p q .
: r z ´+ « >\ " f H Ä »l o < Æl © 7 £ x à ÌZ O (MOCVD) Z O Ü ¼
Ð $ : r AlN × æ ç ß 8 £ x` ¦ s 6 x # Si (111) l ó ø Í0 A\ GaN
~ Ã
Ì} ` ¦ $ í © ¦ $ : r AlN × æ ç ß 8 £ x ¿ ºa \ É r ç H\ P x 9
¸ x 9 ½ ¨ ¸& h , F g < Æ& h : £ ¤$ í ` ¦ ' a ¹ 1 Ï % i .
∗
E-mail: [email protected]
II. ÷ m Ç] M öU ê s0 n É
¸ H GaN ü < AlN 8 £ x É r MOCVD (Veeco , D180GaN)
© q \ ¦ s 6 x # $ í © ÷ &% 3 . GaN $ í © ` ¦ 0 AK (111)
~ ½
Ó ¾ Ó Si (n+ þ A, 0.001 Ω·cm) l ó ø Í` ¦ s 6 x % i . í ß oÓ ü t s
\ O
H ³ ð ` ¦ 0 AK Ã º è7 á x é ß Si ³ ð % o \ ¦ % i [4].
GaN ü < $ : r AlN 8 £ x É r TMGa, TMAl ü < NH
3\ ¦ èÛ ¼ Û
¼ Ð H
2\ ¦ H o # Q Û ¼ Ð 6 x # 1045
◦C, 200 Torr ü
< 720
◦C, 76 Torr \ " f y y $ í © % i . AlN ! Q( 8
£
x $ í © \ @ /ô Ç / B N& ñ ¸| É r É r ë H ³\ [ jy [ O " î ÷ &
#
Qe [5]. 35 nm AlN ! Q( 8 £ x` ¦ s 6 x # 200 nm 1 GaN 8 £ x` ¦ $ í © ¦ Õ ª 0 A\ $ : r AlN × æ ç ß 8 £ x` ¦ $ í © ô Ç Ê
ê 1.5 µm 2 GaN 8 £ x` ¦ $ í © % i . $ : r AlN × æ ç ß 8 £ x
¿
ºa \ ¦ 5 nm, 10 nm, Õ ªo ¦ 20 nm Ð o # $ í ©
%
i . $ : r AlN × æ ç ß 8 £ x` ¦ s 6 x # $ í © ) a 8 £ x _ þ j7 á x ½ ¨
¸ Fig. 1 \ e .
$
: r AlN × æ ç ß 8 £ x ¿ ºa \ É r 2 GaN _ ç H\ P x 9 ¸ H normalski & ³p â (x50) ` ¦ s 6 x # ' a ¹ 1 Ï % i . $ í © ) a 8
£
x _ & ñ $ í ` ¦ ' a ¹ 1 Ï l 0 AK X-ray diffraction (XRD) ü <
X-ray rocking curve (XRC) 8 £ ¤& ñ ` ¦ % i ¦ F g < Æ& h : £ ¤
$ í
` ¦ ' a ¹ 1 Ï l 0 AK photoluminescence (PL) 8 £ ¤& ñ ` ¦
% i .
III. + s ÇÊ Ý õ m Í À X Ø8 ý
Fig. 2 H $ : r AlN × æ ç ß 8 £ x ¿ ºa \ $ í © ô Ç 2
GaN 8 £ x \ @ /ô Ç θ − 2θ Û ¼ ± pô Ç XRD õ s . ¸ H GaN
-287-
-288- ô Dz D GÓ ü t o < Æ rt “D hÓ ü t o ”, Volume 57, Number 4, 2008¸ 10 Z 4
Fig. 1. Schematic of the GaN structure with LT AlN interlayer.
Fig. 2. XRD traces of the GaN films grown on Si (111) substrate with LT AlN interlayer thickness.
8
£
x s é ß & ñ Ü ¼ Ð $ í © < Ê` ¦ · ú Ã º e Ü ¼ 9, GaN (0002) õ
' a > ) a y © ô Çx ß ¼ ' a ¹ 1 Ï÷ &% 3 . s [ þ t õ H GaN 8 £ x s
$ : r AlN × æ ç ß 8 £ x ¿ ºa \ © ' a\ O s Z } É r c−» ¡ ¤ C ¾ Ó
$ í
õ ¦¾ ¡ §| 9 _ & ñ $ í ` ¦ f ` ¦ Ð# ï r . $ : r AlN × æ ç
ß 8 £ x ¿ ºa 5 nm, 10 nm, Õ ªo ¦ 20 nm { 9 M : 2θ ° ú כ
É r 33.85
◦, 34.5
◦, Õ ªo ¦ 34.55
◦ Ð % i H X < s H 2 GaN 8 £ x _ 6 £ x§ 4 (stress) s o H d` ¦ · p . strain relaxation ) a GaN _ 2θ ° ú כ 33.63
◦õ q § 5 nm Ò
re ¦ \ " f H ´ ú § É r 6 £ x§ 4 s 6 x < Ê` ¦ · ú Ã º e % 3 .
Fig. 3 H normalski & ³p â (x 50) Ü ¼ Ð ' a ¹ 1 Ï ) a $ : r AlN × æ ç ß 8 £ x ¿ ºa \ $ í © ô Ç 2 GaN 8 £ x _ ³ ð
s . Fig. 2 (a) ∼ (c) H $ : r AlN × æ ç ß 8 £ x ¿ ºa
5 nm, 10 nm, Õ ªo ¦ 20 nm { 9 M : 1.5 µm $ í © ô Ç 2 GaN ~ Ã Ì} \ @ /ô Ç ³ ð s . ¸ H Ò re ¦ \ " f Ä »o o (mirror-like) ³ ð ` ¦ Ðs ¦ e . $ : r AlN × æ ç ß 8 £ x ¿ ºa
\
É r ç H\ P x 9 ¸ H 5 nm { 9 M : © ´ ú § É r ç H\ P s Ð s
t ë ß 10 nm ¿ ºa \ " f H _ ¸ H ç H\ P s &
Fig. 3. Photomicrographs of the 1.5-¼m-thick GaN sur- face for LT AlN interlayer thicknesses of (a) 5 nm, (b) 10 nm, and (c) 20nm.
20 nm ¿ ºa ÷ & r ç H\ P s ¸F K 7 £ x H â ¾ Ó` ¦
Ð% i . s õ \ " f Ð H % ! 3 $ : r AlN × æ ç ß 8 £ x ¿ ºa _
p [ jô Ç o\ ¸ GaN _ ç H\ P x 9 ¸ © { © y y
>
< Ê` ¦ · ú Ã º e % 3 . 7 £ ¤, $ : r AlN × æ ç ß 8 £ x ¿ ºa
o " f 2 GaN _ 6 £ x§ 4 s o÷ &% 3 l M :ë H כ Ü ¼ Ð ó
ø Íé ß ) a [5]. z ´] j ç H\ P x 9 ¸ H # Qb G> o % i H t · ú
Ðl 0 AK ç H\ P x 9 ¸\ ¦ 8 £ ¤& ñ % i . 5 nm, 10 nm, Õ ª o
¦ 20 nm Ò re ¦ _ ç H\ P x 9 ¸ H y y 70 /cm, 5 /cm, Õ ª o
¦ 30 /cm s % 3 .
$
: r AlN × æ ç ß 8 £ x ¿ ºa \ É r 2 GaN 8 £ x _ & ñ $ í
`
¦ · ú Ðl 0 AK XRC 8 £ ¤& ñ ` ¦ % i . Fig. 4 \ (002) FWHM 8 £ ¤& ñ õ e . $ : r AlN × æ ç ß 8 £ x ¿ º a
7 £ x < Ê\ , GaN 8 £ x _ & ñ $ í s ¾ Ó © H d` ¦ Ðs
20 nm ¿ ºa \ " f ° ú l & ñ $ í s $ ÷ & H â ¾ Ó` ¦
Ðs ¦ e . s õ H ¸ e > ¿ ºa \ ¦ Å # Q r
6 £ x§ 4 ` ¦ ~ Ã Î ç H\ P s µ 1 ÏÒ q t " f & ñ $ í s t l M
:ë H Ü ¼ Ð ó ø Íé ß ) a . 5 nm, 10 nm, Õ ªo ¦ 20 nm _ $ : r AlN × æ ç ß 8 £ x ¿ ºa \ " f (002) FWHM É r y y 933 arcsec, 651 arcsec, Õ ªo ¦ 825 arcsec s % 3 . ¢ ¸ô Ç, XRC x ß ¼ y
© ¸ H (002) FWHM 8 £ ¤& ñ õ ü < { 9 u 9 $ : r AlN
×
æ ç ß 8 £ x ¿ ºa 10 nm { 9 M : © Z } É r x ß ¼y © ¸\ ¦ Ð
. $ : r AlN × æ ç ß 8 £ x ¿ ºa 10 nm { 9 M : © a % ~ É r
&
ñ $ í ` ¦ Ð% i .
$
: r AlN × æ ç ß 8 £ x ¿ ºa F g < Æ& h : £ ¤$ í \ p u H % ò
¾ Ó` ¦ ' a ¹ 1 Ï l 0 AK PL 8 £ ¤& ñ ` ¦ % i . Õ ªa Ë > 5 H © : r
\
" f 8 £ ¤& ñ ) a $ : r AlN × æ ç ß 8 £ x ¿ ºa \ É r 2 GaN 8 £ x _
PL : £ ¤$ í ` ¦ ? / ¦ e . PL x ß ¼ 0 Au H 5 nm − 3.376 eV, 10 nm − 3.376 eV, Õ ªo ¦ 20 nm − 3.385 eV
#
3 0 A\ ¦ t ¦ e Ü ¼ 9 $ : r AlN × æ ç ß 8 £ x ¿ ºa \ x
½ ¨ 7 Hë H Si (111) l ó ø Í0 A\ $ í © ô Ç GaN 8 £ x _ $ : r AlN × æ ç ß 8 £ x ¿ ºa \ É r : £ ¤$ í – ^ ü ½ © -289-
Fig. 4. (002) X-ray rocking curves of GaN layer with LT AlN interlayer thickness.
Fig. 5. PL properties of GaN layer with LT AlN inter- layer thickness at RT.
ß
¼ 0 Au ¸F Km blue-shift ÷ &% 3 . s PL x ß ¼ 0 Au H
s # Q l ó ø Í0 A\ " f strain relaxation ) a GaN _ x ß ¼
Ð 35 ∼ 45 meV ± ú É r ° ú כs [6]. $ : r AlN × æ ç ß 8
£
x ¿ ºa \ " f H blue-shift & ³ © É r Si l ó ø Íõ _
\ P Ø ½ Ó> Ã º s \ _ K biaxial strain ) a GaN 8 £ x \
"
f Ðs H PL x ß ¼ s s 9 s Qô Ç & ³ © É r GaN \ 6
x H stress _ o\ _ ô Ç כ Ü ¼ Ð ó ø Íé ß ) a [5]. ¢ ¸ô Ç,
$
: r AlN × æ ç ß 8 £ x ¿ ºa 7 £ x < Ê\ x ß ¼ y © ¸ H 7 £ x
, PL FWHM É r & h & h y è < Ê` ¦ Ðs 20 nm ¿ ºa
\
" f x ß ¼ y © ¸ H y è, PL FWHM É r 7 £ x < Ê` ¦ Ðs ¦ e
. s õ H · ú ¡_ XRC õ ü < { 9 u ¦ V−/ B G â
¾ Ó` ¦ Ð% i . PL FWHM É r 5 nm − 43.7 meV, 10 nm
− 38.1 meV, Õ ªo ¦ 20 nm − 47.1 meV ` ¦ % 3 % 3 . $
: r AlN × æ ç ß 8 £ x ¿ ºa 10 nm { 9 M : © a % ~ É r PL : £ ¤$ í
`
¦ Ð% i .
IV. + s Ç Â ] Ø
: r ½ ¨\ " f H MOCVD Z O Ü ¼ Ð $ : r AlN × æ ç ß 8 £ x ¿ º a
¸] X ` ¦ : x K Si l ó ø Í0 A\ ¦¾ ¡ §| 9 GaN ~ à Ì} ` ¦ $ í ©
%
i . $ : r AlN × æ ç ß 8 £ x ¿ ºa \ GaN _ ç H\ P x 9 ¸
y > < Ê` ¦ · ú Ã º e % 3 ¦ 10 nm $ : r AlN × æ ç ß 8
£
x ¿ ºa \ " f © & h É r ç H\ P x 9 ¸\ ¦ S X % i . s õ
H $ : r AlN × æ ç ß 8 £ x ¿ ºa 2 GaN $ í © \ e # Q" f
×
æ כ ¹ô Ç % i ½ + É` ¦ < Ê` ¦ · p .
Y
c p w à U Ø ô
[1] G. Cong, Y. Lu, W. Peng, X. Liu, X. Wang and Z.
Wang, J. Crystal Growth 276, 381 (2005).
[2] K. Engl, M. Beer, N. Gmeinwieser, U. T. Schwarz, J. Zweck, W. Wegscheider, S. Miller, A. Miler, H.-J.
Lugauer, G. Br¨ uderl, A. Lell and V. H¨ arle, J. Crystal Growth 289, 6 (2006).
[3] Y. L. Tsai and J. R. Gong, Opt. Mater. 27, 425 (2004).
[4] G. S. Higashi, Y. J. Chabal, G. W. Trucks and K.
Laghavachari, Appl. Phys. Lett. 56, 656 (1990).
[5] Deok Kyu Kim, SAEMULLI (New Phys.) 55, 43 (2007).
[6] S. Chichibu, H. Okumura, S. Nakamura, G. Feuillet, T. Azuhata, T. Sota and S. Yoshida, Jpn. J. Appl.
Phys. 36, 1976 (1997).
-290- ô Dz D GÓ ü t o < Æ rt “D hÓ ü t o ”, Volume 57, Number 4, 2008¸ 10 Z 4
Properties of GaN on a Si(111) substrate for Various LT AlN Interlayer Thicknesses
Deok Kyu Kim
∗Division of Electronics and Information Engineering, Cheongju University, Cheongju 360-746 (Received 31 July 2008)
GaN layers were grown on silicon (111) substrates with low-temperature (LT) AlN interlayers by using metalorganic vapor-phase epitaxy, and the properties of the GaN layers were investigated for various LT AlN interlayer thicknesses. With LT AlN interlayer, cracks in the GaN layer changed sensitively. For 10-nm-thick LT AlN, the density of cracks was 5/cm, the full width at half maximum of the (002) X-ray rocking curve was 651 arcsec, and the full width at half maximum of the bound exciton line was as low as 38.1 meV at 300 K.
PACS numbers: 68.55.-a, 62.20Mk, 81.40.Jj
Keywords: Low-temperature AlN layer, Crack, Silicon (111), Metalorganic chemical vapor deposition
∗
