Vertically oriented epitaxial germanium nanowires on silicon substrates using thin germanium buffer layers.
We demonstrate a method to realize vertically oriented Ge nanowires on Si(111) substrates. Ge nanowires were grown by chemical vapor deposition using Au nanoparticles to seed nanowire growth via a vapor-liquid-solid growth mechanism. Rapid oxidation of Si during Au nanoparticle application inhibits the growth of vertically oriented Ge nanowires directly on Si. The present method employs thin Ge buffer layers grown at low temperature less than 600 degrees C to circumvent the oxidation problem. By using a thin Ge buffer layer with root-mean-square roughness of approximately 2 nm, the yield of vertically oriented Ge nanowires is as high as 96.3%. This yield is comparable to that of homoepitaxial Ge nanowires. Furthermore, branched Ge nanowires could be successfully grown on these vertically oriented Ge nanowires by a secondary seeding technique. Since the buffer layers are grown under moderate conditions without any high temperature processing steps, this method has a wide process window highly suitable for Si-based microelectronics.
Jung
Jae Hun
JH
Department of Physics, Dong-A University, Hadan-2-dong, Sahagu, Busan 604-714, Korea.
Yoon
Hyun Sik
HS
Kim
Yu Lee
YL
Song
Man Suk
MS
Kim
Yong
Y
Chen
Zhi Gang
ZG
Zou
Jin
J
Choi
Duk Yong
DY
Kang
Jung Hyun
JH
Joyce
Hannah J
HJ
Gao
Qiang
Q
Hoe Tan
H
H
Jagadish
Chennupati
C