MBE??GaAs?????????AFM??

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JST-CREST???????????_at_???? (June 29-30, 2006)
MBE??GaAs?????????AFM??
?????????? ?? ?? Masahiro Yoshita
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MBE??(110)??????
?????????
(M. Yoshita et al. JJAP 2001)
490oC???
600oC?????
T?????
??? ?? 6nm
110
?????? ????? ???
????? 14nm
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???????????GaAs??????
???? 600C, 10 min.
GaAs?(nominal) 6nm (30 ML)

Ga ?????????
Ga flux?? 1 /mm (0.3 ML/mm)
M. Yoshita et al. APL 2002 J.-W. Oh et al. APL
2003
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(110)GaAs????????????
n 30 ML
????
23 ML?? ???
1ML?? ?????
M. Yoshita et al. APL 2002 J.-W. Oh et al. JAP
2004
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MBE?????????????
????

• ??????(110) ?????????
• i) ????????????
• ii) ???????????
• (001)?????????
• AlAs?InGaAs???????

T?????????????
???1.?????

• ?????????????
• ????????????????

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(110)??????????????
T 591 C
615 C
627 C
649 C
6 nm (110) GaAs
CEOgrowth(510C) 10 min. anneling
??
?????????????????

1. ??????
2. ???????

????
650C?????? ????????? ?????
??? ??
5um x 5um
40um x 40um
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GaAs???(110)????????
GaAs ???(110)? no MBE growth 10 min. annealing
at 649 C
???????????
650C???????? ???????Ga??desorption
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??????????????
2ML??
_at_ 649C
5mmx5mm
?????????

1. 620630C?????
2. ?????????

???????620-630C?????
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???????????????
6 nm (110) GaAs
CEOgrowth(510C) 10 min. anneling at 650C
50um x 50um
?????????????????????????

• ????????????????
• ????????? 20um

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????????????
100nm GaAs on (110) edge 10 min. annealing at 650C
coverage deviation 5 ML/mm
gt?????
i) ?????? 200 um/ML
20 um
?????????????????
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????????????2
100nm GaAs on (110) edge 10 min. annealing at 650C
(110) sub.
ii) ?????? lt???????
????????????????????????????
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???
??????(110)GaAs???????????????????????????????????
?
1) ????????????????????????????????
2) 650C????????????2ML???????????????
???????Ga???desorption
3) ??????620-630C??????????????????
(110)?????????????????????
1) ???????????????????????????????
??????????????????????
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????????(???)
??????????????????????????????????
??????????????????????? 4?????????
????????
????????? PCF???continuum????????? AR??????
??????2????(??????)
?????????????????
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(001)??????????(001)QW???????
??????????????
????(GI)??????????????
MBE??????????650C
?????????? ????p-p (nm) (????rms)
1) 700nm GaAs 50s-GI 10-16nm (1.8nm)
2) 700nm GaAs 3hrs-GI 1.7nm (0.23nm)
ref. native oxide desorption (no growth) 20-23nm (2.4-2.7nm)
2)
1)
h-scale 3 nm
h-scale 16 nm
ref.
(001)QW???????
?????????
QW?? ???? 610C
h-scale 20 nm
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?????????Ga??As???migration barrier energy
1ML???? ???
Ga adatom
As adatom
GaAs(110)?????migration barrier energy
Atomic Species Migration Direction Barrier Energy (eV)
Ga 110 0.57
Ga 001 0.86
As 110 0.57
As 001 0.67
Ga 110 on (001)b2 1.2
Ga 110 on (001)b2 1.5
cf.
(A.Ishii et al. APL 2003)
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(110)GaAs???????????????
1ML???????
23ML?????
M. Yoshita et al. APL 2002