½ ¨ 7 Hë H Sae Mulli (The Korean Physical Society), Volume 59, Number 4, 2009¸ 10 Z 4, pp. 361∼364
$
[Æ X Ø AlN ú n Þ m « כ qø m É; c 8 ý X ¢ Si (111) M m ü; c V R ËX ê s X ¢ GaN «8 ý ¤V R Ë
»% ¦ ∗ · » ý ¡9
' õ
AÅ Ò@ / < Æ § & ñ Ð/ B N < ÆÂ Ò, ' õ AÅ Ò 360-746 (2009¸ 4 Z 4 15{ 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 ¶ ú { 9 \ É r : £ ¤$ í ` ¦ ½ ¨ % i . $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 < ÊÜ ¼ Ð" f 2 GaN 8 £ x _ ç H\ P x 9
¸ H 300/cm \ " f 5/cm Ð / å L y y è % i . ¢ ¸ô Ç, $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 Ü ¼ Ð K (002) X-ray rocking curve _ full width at half maximum É r 680 sec
−1\ " f 651 sec
−1 Ð ¾ Ó © ÷ &% 3 ¦ 300 K\ " f 8
£ ¤& ñ ô Ç photoluminescence_ full width at half maximum ¸ 52.4 meV\ " f 38.1 meV Ð ¾ Ó © ÷ &% 3 .
PACS numbers: 68.55.-a, 62.20.Mk, 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 µm s © _ 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], SiN
x[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 Í 0 A\ GaN ~ Ã Ì }
` ¦ $ í © ¦ $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ _ ô Ç ç H\ P x 9 ¸ x 9
½ ¨ ¸& h , F g < Æ& h : £ ¤$ í ` ¦ ' a ¹ 1 Ï % i .
II. ÷ m Ç] M öU ê s0 n É
∗
E-mail: [email protected]; +82-43-229-8461
Fig. 1. Schematic of the GaN structure with LT AlN interlayer.
¸ 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 Ωcm) 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 H 10 nm Ð $ í © % i . $ : r AlN × æ ç ß 8 £ x` ¦ s 6 x # $ í ©
)
a 8 £ x _ þ j7 á x ½ ¨ ¸ H Fig. 1 õ ° ú .
$
: r AlN × æ ç ß 8 £ x ¶ ú { 9 \ É r 2 GaN_ ³ ð ` ¦ atomic force microscopy (AFM)` ¦ s 6 x # ' a ¹ 1 Ï % i .
$ í
© ) a 8 £ x _ & ñ $ í ` ¦ ' a ¹ 1 Ï l 0 AK x-ray diffraction
-361-
-362- ô Dz D GÓ ü t o < Æ rt “D hÓ ü t o ”, Volume 59, Number 4, 2009¸ 10 Z 4
Fig. 2. AFM images of the 1.5-µm-thick GaN surface (a) without and (b) with LT AlN interlayer.
(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
Figure 2 H AFM Ü ¼ Ð ' a ¹ 1 Ï ) a $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9
t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò re ¦ _ 2 GaN 8 £ x _ ³ ð
s . Fig. 2(a) H $ : r AlN × æ ç ß 8 £ x s \ O H Ò re ¦ s
¦ (b) H $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 ô Ç Ò re ¦ Ð 1.5 µm $ í © ô Ç 2 GaN 8 £ x \ @ /ô Ç ³ ð s . ¿ º Ò re ¦ \
Fig. 3. XRD traces of the GaN films grown on Si (111) substrate without and with LT AlN interlayer.
"
f Ä »o o(mirror-like) ³ ð ` ¦ % 3 % 3 . GaN 8 £ x _ _ Û
¼(terrace) ½ ¨ ¸ Ðs ¦ e t ë ß $ : r AlN × æ ç ß 8 £ x s
\ O
H Ò re ¦ \ " f 7 á § 8 ç H{ 9 ô Ç _ Û ¼ ½ ¨ ¸\ ¦ f ` ¦ S X
% i . ¢ ¸ô Ç, $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 ô Ç Ò re ¦ \ " f
< Ê(threading dislocation)s 7 £ x ô Ç S X % i . ì ø Í
\ , $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 < ÊÜ ¼ Ð" f ç H\ P x 9 ¸ H 300 /cm \ " f 5 /cm Ð / å L y y è % i . ç H\ P x 9 ¸ H F g < Æ
&
³p â ` ¦ s 6 x # 8 £ ¤& ñ % i . s õ \ " f Ð H %
!
3 $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ _ K 2 GaN _ < Êõ ç
H\ P x 9 ¸ © { © y y > < Ê` ¦ e H X < s H $ : r AlN × æ ç ß 8 £ x s ¶ ú { 9 ÷ & " f 2 GaN_ 6 £ x§ 4 s y è÷ &% 3 l
M :ë H כ Ü ¼ Ð ó ø Íé ß ) a [5]. $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9
t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò re ¦ _ } 9 l (roughness) H y
y 4.37 ˚ A õ 4.40 ˚ A Ü ¼ Ð q 5 p w % i .
Figure 3 É r $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ
¶ ú
{ 9 ô Ç Ò re ¦ _ 2 GaN 8 £ x \ @ /ô Ç θ-2θ Û ¼ ± pô Ç XRD õ
s . ¿ º Ò re ¦ _ GaN 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 2θ = 34.5
◦\ " f ' a ¹ 1 Ï÷ &% 3 . s [ þ t õ H GaN 8 £ x s $ : r AlN
×
æ ç ß 8 £ x ¶ ú { 9 \ © ' a\ O s Z } É r c-» ¡ ¤ C ¾ Ó$ í õ ¦¾ ¡ §| 9 _
& ñ $ í ` ¦ f ` ¦ Ð# ï r . XRD x ß ¼ y © ¸ H $ : r AlN
×
æ ç ß 8 £ x` ¦ ¶ ú { 9 ô Ç Ò re ¦ \ " f 7 á § 8 y © > z ¤ .
$
: r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò r e
¦ _ 2 GaN 8 £ x _ & ñ $ í ` ¦ · ú Ðl 0 AK XRC 8 £ ¤& ñ
`
¦ % i . Fig. 4\ (002) full width at half maximum (FWHM) 8 £ ¤& ñ õ e . $ : r AlN × æ ç ß 8 £ x` ¦
¶ ú
{ 9 < ÊÜ ¼ Ð" f, 2 GaN 8 £ x _ & ñ $ í s ¾ Ó © H d` ¦ Ð% i .
s
õ H $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ _ K 6 £ x§ 4 s ¢ - a o÷ &
" f & ñ $ í s ¾ Ó © ) a כ Ü ¼ Ð ó ø Íé ß ) a . $ : r AlN × æ ç ß 8
£
x` ¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò re ¦ _ (002) FWHM
½ ¨ 7 Hë H $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ _ ô Ç Si (111) l ó ø Í0 A\ $ í © ô Ç GaN 8 £ x _ : £ ¤$ í – ^ ü ½ © · ^ < ª C -363-
Fig. 4. (002) X–ray rocking curves of GaN layer without and with LT AlN interlayer.
É
r y y 680 sec
−1õ 651 sec
−1s % 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` ¦ ¶ ú { 9 ô Ç Ò re ¦ \ " f 8 y © ô Ç x ß ¼y © ¸\ ¦ Ð% i .
$
: r AlN × æ ç ß 8 £ x s F g < Æ& h : £ ¤$ í \ p u H % ò ¾ Ó` ¦
'
a ¹ 1 Ï l 0 AK PL 8 £ ¤& ñ ` ¦ % i . Fig. 5 H © : r \ " f 8
£ ¤& ñ ) a $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ ¶ ú { 9 ô
Ç Ò re ¦ _ 2 GaN 8 £ x _ PL : £ ¤$ í ` ¦ ? / ¦ e . $
: r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò re ¦ _ PL x ß ¼ 0 Au H y y 3.392 eV Õ ªo ¦ 3.376 eV\ ¦ t
¦ e Ü ¼ 9 $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ x ß ¼ 0 Au
red-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 30 ∼ 45 meV
± ú
É r ° ú כs [6]. $ : r AlN × æ ç ß 8 £ x ¶ ú { 9 \ " f
H red-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 6 £ x§ 4 _ o\ _ ô Ç
כ
Ü ¼ Ð ó ø Íé ß ) a [5]. 7 £ ¤, $ : r AlN × æ ç ß 8 £ x s ¶ ú { 9 H d Ü ¼
Ð" f 2 GaN 8 £ x _ 6 £ x§ 4 ` ¦ ¢ - a o # H & ³ © s
. ¢ ¸ô Ç, $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 < ÊÜ ¼ Ð" f x ß ¼ y © ¸ü <
PL FWHM ¸¿ º y è < Ê` ¦ Ðs ¦ e . s õ H · ú ¡_ XRC õ ü < { 9 u H â ¾ Ó` ¦ Ð% i . $ : r AlN × æ ç ß 8 £ x
`
¦ ¶ ú { 9 t · ú § É r Ò re ¦ õ ¶ ú { 9 ô Ç Ò re ¦ _ PL FWHM É r y
y 52.4 meV, 38.1 meV` ¦ % 3 % 3 Ü ¼ 9 $ : r AlN × æ ç ß 8 £ x
`
¦ ¶ ú { 9 < ÊÜ ¼ Ð" f F g < Æ& h : £ ¤$ í s ¾ Ó © H d` ¦ · ú Ã º e % 3 .
IV. + s Ç Â ] Ø
: r ½ ¨\ " f H MOCVD Z O Ü ¼ Ð $ : r AlN × æ ç ß 8 £ x ¶ ú { 9
< ÊÜ ¼ Ð" f Si l ó ø Í0 A\ ¦¾ ¡ §| 9 GaN ~ à Ì} ` ¦ $ í © % i
Fig. 5. PL properties of GaN layer without and with LT AlN interlayer at RT.
. $ : r AlN × æ ç ß 8 £ x` ¦ ¶ ú { 9 < ÊÜ ¼ Ð" f 2 GaN_ ç H\ P x 9
¸ / å L > y è < Ê` ¦ · ú Ã º e % 3 ¦ & ñ $ í õ F g < Æ
&
h
: £ ¤$ í \ e # Q" f ¸ ¾ Ó © ) a : £ ¤$ í ` ¦ S X % i . s õ
H $ : r AlN × æ ç ß 8 £ x s 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] D. K. Kim, Sae Mulli 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).
-364- ô Dz D GÓ ü t o < Æ rt “D hÓ ü t o ”, Volume 59, Number 4, 2009¸ 10 Z 4
Properties of GaN on a Si(111) Substrate with a LT AlN Interlayer Inserted
Deok Kyu Kim
∗and Hong Bae Kim
Division of Electronics and Information Engineering, Cheongju University, Cheongju 360-746 (Received 15 April 2009)
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 with a LT AlN interlayer inserted were investigated. The insertion of the LT AlN interlayer decreased the crack density of the 2nd GaN layer from 300 /cm to 5 /cm, sensitively. Also, the full width at half maximum of the (002) X-ray rocking curve was improved from 680 sec
−1to 651 sec
−1, and the full width at half maximum of the bound exciton line was improved from 52.4 meV to 38.1 meV in photoluminescence measurements 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
∗
