N AN O E X P R E S S Open Access
Amorphous Silicon Nanowires Grown on
Silicon Oxide Film by Annealing
, Chengyong Wang
, Ke Chen
, Zhonghua Ni
and Yunfei Chen
In this paper, amorphous silicon nanowires (α-SiNWs) were synthesized on (100) Si substrate with silicon oxide film
by Cu catalyst-driven solid-liquid-solid mechanism (SLS) during annealing process (1080 °C for 30 min under Ar/H
atmosphere). Micro size Cu pattern fabrication decided whether α-SiNWs can grow or not. Meanwhile, those micro
size Cu patterns also controlled the position and density of wires. During the annealing process, Cu pattern reacted
to form Cu silicide. More important, a diffusion channel was opened for Si atoms to synthesis α-SiNWs.
What is more, the size of α-SiNWs was simply controlled by the annealing time. The length of wire was increased
with annealing time. However, the diameter showed the opposite tendency. The room temperature resistivity of
the nanowire was about 2.1 × 10
Ω·cm (84 nm diameter and 21 μm length). This simple fabrication method makes
application of α-SiNWs become possible.
Keywords: α-SiNWs, Cu patterns, Annealing time, Resistivity
Among the various classes of one-dimensional semicon-
ductor nanostructure, silicon nanowire (SiNW) has been ex-
hibited bright future in the fields of electronic, photovoltaic
solar, photonic, battery, and sensor. [1–6] The SiNW
manufacture method includes top-down and bottom-up ap-
proaches. Table 1 is the summary of different SiNW manu-
facture method. Top-down approach is usually realized by
reactive ion etching (RIE) and metal-catalyzed electroless
etching of silicon. In those methods, nanowire site is con-
trolled in top-down approach by nanofabrication tools such
as e-beam lithography,  nanoimprint lithography , or
nanosize template such as PS sphere,  AAO mask .
Nanofabrication tools control the site, size, orientation, and
numbers of wire well with high-cost and complex fabrica-
tion process. Nanosize template [9–11] is the low-cost
method, but the fabrication process is more complex than
nanofabrication tool method for template should be built
and removed during the whole process. Therefore,
template-free method shows good potential in future .
Another top-down approach uses MEMS technique to fab-
ricate site controllable SiNWs , this fabrication process
easily fabricate SiNW sensor devices. However, MEMS tech-
nique brings complex manufacture process with high cost.
In bottom-up approach, chemical vapor deposition
(CVD) is an important approach to synthesis SiNWs
with low-cost and simple fabrication process. And this
approach can readily produce extremely small diameter
and super long SiNWs (as recorded, the smallest diam-
eter was 1 nm, and the longest was millimeters) [14–16].
Good quality SiNWs are always synthesized through
vapor-liquid-solid (VLS) mechanism with the help of Au
or other metals in this method . However, those novel
materials are prohibited in clean rooms for degrading
the electrical and optical properties of semiconductors.
Catalyst free method is put forward to solve pollution
problem which brought by novel catalysts in bottom-up
approach. Oxide-assisted growth (OAG) method does not
require any metal catalyst . Unfortunately, the compati-
bility with Si-based integration technology is poor in this
method. And products are always affected by other residual
impurities easily . Room temperature continuous wave
laser ablation of Si is another way to synthesis SiNWs with-
out using metal catalyst . Nevertheless, high vacuum is
needed. Even in the simple SiO evaporation technique,
good size controllability is always hard to realize. Moreover,
SiO powder is harmful to health .
* Correspondence: email@example.com
School of Electromechanical Engineering, Guangdong University of
Technology, Guangzhou 510006, China
Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano
Biomedical Instruments, Southeast University, Nanjing 211189, China
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
Yuan et al. Nanoscale Research Letters (2017) 12:487