We have found that a Si wire array is formed by thermal agglomeration of an ultrathin (111) Si layer in a bonded silicon-on-insulator (SOI) structure, although previous studies for crystalline and amorphous Si layers on SiO2 only showed island formation. As starting material, (111) bonded SOI wafers with the top Si layers thinned to 5–9 nm were used. The samples were then subjected to a thermal treatment at 950 °C in an ultrahigh vacuum. Atomic force microscopy revealed that the (111) top Si layer is deformed into three sets of wire arrays in the three equivalent 112¯ directions. It is also shown that the patterning of a Si layer leads to the wire array selectively formed in one of these three directions.

1.
Y.
Ono
,
M.
Nagase
,
M.
Tabe
, and
Y.
Takahashi
,
Jpn. J. Appl. Phys., Part 1
34
,
1728
(
1995
).
2.
N.
Sugiyama
,
T.
Tezuka
, and
A.
Kurobe
,
J. Cryst. Growth
192
,
395
(
1998
).
3.
Y.
Wakayama
,
T.
Tagami
, and
S.
Tanaka
,
J. Appl. Phys.
85
,
8492
(
1999
).
4.
B.
Legrand
,
V.
Agache
,
T.
Melin
,
J. P.
Nys
,
V.
Senez
, and
D.
Stievenard
,
J. Appl. Phys.
91
,
106
(
2002
).
5.
R.
Nuryadi
,
Y.
Ishikawa
, and
M.
Tabe
,
Appl. Surf. Sci.
159
,
121
(
2000
).
6.
R.
Nuryadi
,
Y.
Ishikawa
,
Y.
Ono
, and
M.
Tabe
,
J. Vac. Sci. Technol. B
20
,
167
(
2002
).
7.
Y.
Ishikawa
,
M.
Kumezawa
,
R.
Nuryadi
, and
M.
Tabe
,
Appl. Surf. Sci.
190
,
11
(
2002
).
8.
Y.
Ishikawa
,
Y.
Imai
,
H.
Ikeda
, and
M.
Tabe
,
Appl. Phys. Lett.
83
,
3162
(
2003
).
9.
J.
Camassel
,
L. A.
Falkovsky
, and
N.
Planes
,
Phys. Rev. B
63
,
035309
(
2001
).
10.
T. T.
Tsong
,
Prog. Surf. Sci.
64
,
199
(
2000
).
11.

The detailed TEM observation showed that the bottom of the Si wire near the sidewalls is slightly depressed into the underlying SiO2. This is probably due to the evaporation of slight amount of Si atoms as SiO molecules, although such a phenomenon is difficult to be detected by the volume analysis based on the AFM observation.

12.
D. J.
Eaglesham
,
A. E.
White
,
L. C.
Feldman
,
N.
Moriya
, and
D. C.
Jacobson
,
Phys. Rev. Lett.
70
,
1643
(
1993
).
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