ƒ ½ ¨ 7 Hë H Sae Mulli (The Korean Physical Society), Volume 57, Number 6, 2008¸ 12 Z 4, pp. 398∼401

 ƒ  ½ ¨ 7 Hë  H  Sae Mulli (The Korean Physical Society), Volume 57, Number 6, 2008¸   12 Z 4, pp. 398∼401

$

[Æ X Ø AlN ú n އ ˜ m • « T “ Ó Þ # b V R ËX ê s” X ¢ GaN • «8 ý 1  GaN ‘ ¤B s; c   \ ¥ — ¤V R Ë

™ »%
¦  ^∗

' õ

AÅ Ò@ /† < Ɠ § „   & ñ ˜ Ð/ B N † < Æ Ò, ' õ AÅ Ò 360-746 (2008¸   7 Z 4 16{ 9  ~ à Î6 £ §)

Ä

»l  o† < Æl  © œ7 £ x ‚ à ÌZ O Ü ¼– Ð $ “ : r AlN ×  æ ç ß –8 £ x`  ¦ s 6   x # Œ Si(111) l ó ø Í0 A\  GaN ~ à Ì} Œ •`  ¦ $ í  © œ “ ¦ $ 

“ :

r AlN ×  æ ç ß –8 £ x  A _  1  GaN ¿ ºa \    É r : £ ¤$ í `  ¦ ƒ  ½ ¨ % i  . 1  GaN ¿ ºa \     GaN 8 £ x _  ç 

H\ P s    y Œ ™ >    † < Ê`  ¦ · ú ˜ à º e ” % 3 “ ¦ 0.2 µm ¿ ºa \ " f ç  H\ P x 9 • ¸ 30/cm _   © œ & h “ É r ç  H\ P `  ¦ % 3 % 3 



. ¢ ¸ô  Ç, (002) X-ray rocking curve _  full width at half maximum 8 £ ¤& ñ   õ  686 arcsec _    & ñ

$ í

`  ¦ ° ú   H ~ à Ì} Œ •`  ¦ % 3 % 3 “ ¦ photoluminescence 8 £ ¤& ñ   õ  300 K \ " f 46.1 meV _  full width at half maximum `  ¦ % 3 % 3  .

PACS numbers: 68.55.-a, 62.20Mk, 81.40.Jj

Keywords: 1  GaN 8 £ x, $ “ : r AlN ×  æ ç ß –8 £ x, ç  H\ P , z  ´o – B H (111), Ä »l  o† < Æl  © œ7 £ x ‚ à Ì

I. " e  ] Ø

þ

j   H \ , Si l ó ø ͓ É r $    o, @ /6   x | ¾ Ó o, Õ ªo “ ¦ a % ~“ É r \ P  x 9

 „  l & h  „  • ¸$ í 1 p x _   © œ& h  M :ë  H \  GaN _  $ í  © œ l ó ø Í Ü

¼– Ð ´ ú §“ É r › ' a d ” `  ¦ ~ à Î š ¸“ ¦ e ”  . t ë ß –, GaN ü < Si l  ó

ø Í s _   H     © œÃ º Ô  ¦{ 9 u ü < \ P Ø Ÿ ‚ ½ Ó > à º_  s – Ð

“

 K  µ 1 ÏÒ q t   H GaN ç  H\ P s  Si l ó ø Í`  ¦ s 6   x ô  Ç GaN _  $ í



© œ\    a Ë >[  t ÷ &“ ¦ e ”  . ´ ú §“ É r ƒ  ½ ¨ [ þ t“ É r Si l ó ø Í\ " f # Œ

Q t  ! Q( 8 £ x`  ¦  6   x # Œ “ ¦¾ ¡ §| 9 , Á ºç  H\ P  GaN \  ¦ % 3  l

 0 AK  ” ¸§ 4  % i Ü ¼
, 1 µm s  © œ_  Á ºç  H\ P  GaN $ í  © œ

l  ' p é ß –{ 9  ! Q( 8 £ x ë ß –Ü ¼– Ѝ  H ô  Ç>  e ” % 3  . s ü < ° ú  “ É r s

Ä »– Ð ×  æ ç ß –8 £ x`  ¦ ¶ ú š{ 9    H ~ ½ ÓZ O s  • ¸{ 9 ÷ &% 3 “ ¦ ×  æ ç ß –8 £ x Ü ¼

–

Ð $ “ : r AlN [1], SiN

[2], Õ ªo “ ¦  ×  æ8 £ x [3] 1 p x`  ¦ s 6   x 



 H ƒ  ½ ¨ ”  ' Ÿ ÷ &“ ¦ e ”  . Õ ª ×  æ \ " f• ¸ $ “ : r AlN ×  æ ç ß –8 £ x

`

 ¦ s 6   x ô  Ç $ í  © œZ O “ É r ç ß –é ß – €  " f   & ñ   † < Êõ  ç  H\ P `  ¦ 1 l x r

\  ×  ¦{ 9  à º e ”   H $ í  © œZ O Ü ¼– Ð · ú ˜ 94 R e ”  . Õ ª Q
, a % ~

“ É

r : £ ¤$ í `  ¦ ° ú   H $ í  © œZ O e ” \ • ¸ Ô  ¦ ½ ¨ “ ¦ $ “ : r AlN ×  æ ç ß – 8

£

x $ í  © œZ O \  @ /ô  Ç ƒ  ½ ¨  H  f ”  p q   .

‘

: r z  ´+ « >\ " f  H Ä »l  o† < Æl  © œ7 £ x ‚ à ÌZ O  (MOCVD) Z O Ü ¼

–

Ð $ “ : r AlN ×  æ ç ß –8 £ x`  ¦ s 6   x # Œ Si(111) l ó ø Í0 A\  GaN

~ Ã

Ì} Œ •`  ¦ $ í  © œ “ ¦ $ “ : r AlN ×  æ ç ß –8 £ x  A _  1  GaN ¿ º a

\    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

—

¸Ž  H GaN ü < AlN 8 £ x“ É r MOCVD (Veeco  , D180GaN)



© œq \  ¦ s 6   x # Œ $ í  © œ ÷ &% 3  . GaN $ í  © œ`  ¦ 0 AK  (111)

~ ½

ӆ 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  à º™ è7 á x é ß – Si ³ ð€   % ƒo \  ¦ % i   [4].

GaN ü < $ “ : r AlN 8 £ x“ É r TMGa, TMAl ü < NH

\  ¦ ™ èÛ ¼

Û ¼– Ð H

\  ¦ H o # Q Û ¼– Ð  6   x # Œ 1045

C, 200 Torr ü

< 720

C, 76 Torr \ " f y Œ •y Œ • $ í  © œ % i  . AlN ! Q( 8 £ x

$ í

 © œ\  @ /ô  Ç / B N& ñ › ¸| “ É r   É r ë  H‰  ³\   [ jy  [ O " î ÷ &# Q e ”

  [5]. 35 nm AlN ! Q( 8 £ x`  ¦ s 6   x # Œ 1  GaN 8 £ x $ í



© œ “ ¦ Õ ª 0 A\  20 nm $ “ : r AlN ×  æ ç ß –8 £ x`  ¦ $ í  © œô  Ç Ê ê 2.5 µm 2  GaN 8 £ x`  ¦ $ í  © œ % i  . 1  GaN _  ¿ ºa \  ¦ €  • 100 nm, 200 nm, 400 nm, Õ ªo “ ¦ 600 nm – Ð    o # Œ

$ í

 © œ % i  . $ “ : r AlN \  ¦ s 6   x # Œ $ í  © œ  ) a 8 £ x _  þ j7 á x ½ ¨

›

¸ Fig. 1 \ 
 
e ”  .

1  GaN ¿ ºa \    É r 2  GaN _  ç  H\ P x 9 • ¸  H nor- malski ‰ & ³p  â (x50) `  ¦ s 6   x # Œ › ' a ¹ 1 Ï % i  . $ í  © œ  ) 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 normalski ‰ & ³p  â (x 50) Ü ¼– Ð › ' a ¹ 1 Ï  ) a 1 

GaN 8 £ x ¿ ºa \     $ í  © œô  Ç 2  GaN 8 £ x _  ³ ð€   ”  s 

-398-

 ƒ  ½ ¨ 7 Hë  H  $ “ : r AlN ×  æ ç ß –8 £ x s 6   x # Œ $ í  © œô  Ç GaN 8 £ x _  1  GaN ¿ ºa \    É r : £ ¤$ í – ^ ”  ü ½ © -399-

Fig. 1. Schemetic of the GaN structure with LT AlN interlayer.

Fig. 2. Photomicrographs of the 2.5-¼m-thick GaN sur- face for 1st GaN thicknesses of (a) 0.1 µm, (b) 0.2 µm, (c) 0.4 µm, and (d) 0.6 µm.



. Fig. 2 (a) ∼ (d)   H 1  GaN ¿ ºa  0.1 µm, 0.2 µm, 0.4 µm, Õ ªo “ ¦ 0.6 µm { 9  M : €  • 2.5 µm $ í  © œô  Ç 2  GaN

~ Ã

Ì} Œ •\  @ /ô  Ç ³ ð€  s  . — ¸Ž  H Ò  re  ¦ \ " f Ä »o  o(miror-like)

³

ð€  `  ¦ ˜ Ðs “ ¦ e ”  . 1  GaN ¿ ºa  0.2 µm { 9  M :, 2  GaN _  ç  H\ P x 9 • ¸  © œ & h 6 £ §`  ¦ · ú ˜ à º e ” % 3 “ ¦ Õ ª ü @_ 

¿

ºa \ " f  H ç  H\ P x 9 • ¸  _  q 5 p w † < Ê`  ¦ ˜ Ðs “ ¦ e ”  . Õ ª o

“ ¦, 1  GaN ¿ ºa _  & h “ É r    o\ • ¸ 2  GaN_  ç  H\ P x 9 

•

¸  © œ{ © œy    y Œ ™ >    † < Ê`  ¦ · ú ˜ à º e ”  . 7 £ ¤, 1  GaN

¿

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  . ç  H\ P  x 9

• ¸  H # Œ Q ~ ½ ӆ ¾ ÓÜ ¼– Ð ‚  `  ¦ Õ ª# Q Õ ª ‚  õ    u   H ç  H\ P  _

 > hà º\  ¦ ¨ î ç  H& h Ü ¼– Ð ½ ¨ô  Ç  כ s  . 0.1 µm, 0.2 µm, 0.4 µm, Õ ªo “ ¦ 0.6 µm Ò  re  ¦ _  ç  H\ P x 9 • ¸  H y Œ •y Œ • 100 /cm, 30 /cm, 70 /cm, Õ ªo “ ¦ 60 /cm s % 3  .

Fig. 3   H 1  GaN ¿ ºa \     $ í  © œô  Ç 2  GaN 8 £ x \ 

@

/ô  Ç θ − 2θ Û ¼ ± pô  Ç XRD   õ s  . — ¸Ž  H GaN 8 £ x s  é ß –

Fig. 3. XRD traces of the GaN films grown on Si (111) substrate with 1st GaN thickness.

Fig. 4. (002) X-ray rocking curves of GaN layer with 1st GaN thickness.

 

& ñ Ü ¼– Ð $ í  © œ† < Ê`  ¦ · ú ˜ à º e ” Ü ¼ 9, GaN (0002) €  õ  › ' a > 

 )

a y © œô  Çx ß ¼ 2θ = 34.5

\ " f › ' a ¹ 1 Ï÷ &% 3  . s [ þ t   õ   H GaN 8 £ x s  1  GaN ¿ ºa \   © œ › ' a\ O s  Z  }“ É r c-» ¡ ¤ C † ¾ Ó$ í õ

 “ ¦¾ ¡ §| 9 _    & ñ $ í `  ¦ f ” `  ¦ ˜ Ð# Œï  r  .

1  GaN ¿ ºa \    É r 2  GaN 8 £ x _    & ñ $ í `  ¦ · ú ˜ ˜ Ð l

 0 AK  XRC 8 £ ¤& ñ `  ¦ % i  . Fig. 4 \  (002) FWHM 8 £ ¤

&

ñ   õ 
 
 e ”  . 1  GaN ¿ ºa  7 £ x † < Ê\    , GaN 8 £ x _    & ñ $ í s  † ¾ Ó © œ H † d`  ¦ ˜ Ðs   0.6 µm ¿ ºa \ 

"

f ° ú š l    & ñ $ í s  $  ÷ &  H  ⠆ ¾ Ó`  ¦ ˜ Ðs “ ¦ e ”  . 0.1 µm, 0.2 µm, 0.4 µm, Õ ªo “ ¦ 0.6 µm_  1st GaN ¿ ºa \ " f (002) FWHM “ É r y Œ •y Œ • 797 arcsec, 686 arcsec, 563 arcsec, Õ

ªo “ ¦ 851 arcsec s % 3  . ¢ ¸ô  Ç, XRC x ß ¼ y © œ• ¸  H 0.4 µm ¿ ºa \ " f  © œ Z  }“ É r x ß ¼y © œ• ¸\  ¦ ˜ Ð% i “ ¦ 0.6 µm ¿ ºa 

\

" f  © œ ± ú “ É r x ß ¼y © œ• ¸\  ¦ ˜ Ð% i  .

-400- ô  Dz D GÓ ü t o † < Æ rt  “D hÓ ü t o ”, Volume 57, Number 6, 2008¸   12 Z 4

Fig. 5. PL properties of GaN layer with 1st GaN thick- ness at RT.

1  GaN ¿ ºa  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  © œ“ : r \ " f 8 £ ¤& ñ

 )

a 1  GaN ¿ ºa \    É r 2  GaN 8 £ x _  PL : £ ¤$ í `  ¦
 

?

/“ ¦ e ”  . PL x ß ¼ 0 Au   H 0.1 µm - 3.402 eV, 0.2 µm - 3.39 eV, 0.4 µm - 3.397 eV, Õ ªo “ ¦ 0.6 µm - 3.388 eV

#

3 0 A\  ¦ t “ ¦ e ” Ü ¼ 9 — ¸Ž  H Ò  re  ¦ s  1  GaN ¿ ºa \   



 x ß ¼ 0 Au  › ¸F Km ”  red-shift ÷ &% 3  . s  PL x ß ¼ 0 A u

  H   s # Q l ó ø Í0 A\ " f strain relaxation  ) a GaN _  x

ß ¼˜ Ð  €  • 20 ∼ 40 meV ± ú “ É r ° ú כs   [6]. 1st GaN ¿ º a

\    " f
 
  H red-shift ‰ & ³ © œ“ É r Si l ó ø Íõ _  \ P Ø Ÿ 

‚

½ Ó> à º s \  _ K  biaxial strain  ) a GaN 8 £ x \ " f ˜ Ðs 



 H PL x ß ¼   s s  9 s  Qô  Ç ‰ & ³ © œ“ É r GaN \   Œ •6   x   H stress _     o\  _ ô  Ç  כ Ü ¼– Ð ó ø Íé ß –  ) a   [5]. 1  GaN ¿ º a

    o\     PL x ß ¼ 0 Au _  { 9 & ñ ô  Ç  ⠆ ¾ Ó$ í “ É r S X ‰ “  

÷

&t  · ú §€ Œ ¤ . ¢ ¸ô  Ç, 1st GaN ¿ ºa  7 £ x † < Ê\     x ß ¼ y

© œ• ¸ü < PL FWHM “ É r & h & h  7 £ x † < Ê`  ¦ ˜ Ðs   0.6 µm

¿

ºa \ " f x ß ¼ y © œ• ¸ü < PL FWHM  y Œ ™™ è† < Ê`  ¦ ˜ Ðs “ ¦ e ”

 . PL FWHM “ É r 0.1 µm - 45.2 meV, 0.2 µm - 46.1 meV, 0.4 µm - 46.4 meV, Õ ªo “ ¦ 0.6 µm - 43.9 meV `  ¦

% 3

% 3  .

IV. + s Ç Â ] Ø

‘

: r ƒ  ½ ¨\ " f  H MOCVD Z O Ü ¼– Ð $ “ : r AlN ×  æ ç ß –8 £ x`  ¦

¶ ú

š{ 9  “ ¦ 1  GaN ¿ ºa › ¸] X `  ¦ : Ÿ x K  Si l ó ø Í0 A\  “ ¦¾ ¡ §| 9  GaN ~ à Ì} Œ •`  ¦ $ í  © œ % i  . 1  GaN ¿ ºa \     GaN _  ç

 H\ P  x 9 • ¸   y Œ ™ >    † < Ê`  ¦ · ú ˜ à º e ” % 3 “ ¦ 0.2 µm 1  GaN ¿ ºa \ " f  © œ & h “ É r ç  H\ P  x 9 • ¸\  ¦ S X ‰ “   % i  . s     õ

  H 1  GaN 8 £ x s  $ “ : r AlN ×  æ ç ß –8 £ x ¶ ú š{ 9  / B N& ñ \  e ” # Q

"

f ×  æ כ ¹ô  Ç % i ½ + É`  ¦ † < Ê`  ¦
  · p .

Y

c p w Š 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).

 ƒ  ½ ¨ 7 Hë  H  $ “ : r AlN ×  æ ç ß –8 £ x s 6   x # Œ $ í  © œô  Ç GaN 8 £ x _  1  GaN ¿ ºa \    É r : £ ¤$ í – ^ ”  ü ½ © -401-

Properties of GaN Grown by Using Low-temperature an AlN Interlayers as a Function of the 1st GaN Layer’s Thickness

Deok Kyu Kim

Division of Electronics and Information Engineering, Cheongju University, Cheongju 360-746 (Received 16 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 as a function of the 1st GaN layer’s thickness were investigated. For variious tkickness of the 1st GaN layer, the density of cracks in the GaN layer changed sensitively. For 0.2-µm-thick 1st GaN Layer, the density of cracks was 30/cm, the full width at half maximum of the (002) X-ray rocking curve was 686 arcsec, and the full width at half maximum of the bound exciton line was as low as 46.1 meV at 300 K.

PACS numbers: 68.55.-a, 62.20Mk, 81.40.Jj

Keywords: 1st GaN layer, Low-temperature AlN interlayer, Crack, Silicon (111), Metalorganic chemical vapor deposition

∗

E-mail: [email protected]