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Volume 3, Issue 2
ISSN: 2470-9905
Crystallography 2017
October 16-17, 2017
2
nd
International Conference on
October 16-17, 2017 | Chicago, USA
Applied Crystallography
Fabrication of single crystal silicon nanowires by metal assisted chemical etching with nanoimprinted
barrier pattern
Seok-min Kim
and
Jonghyun Ju
Chung-Ang University, Republic of Korea
T
o fabricate the silicon nanowires, various methods such as vapor-liquid-solid growth, reactive ion etching with barrier pattern,
oblique angle deposition and metal assisted chemical etching (MACE) have been developed. The MACE can provides a high
aspect ratio and undamaged single crystal silicon nanostructures using low-cost wet etching process. In the MACE process, a
patterned noble metallic structure etches the silicon substrate anisotropically in aqueous solutions containing hydrogen fluoride and
an oxidant, and an isolated single crystal vertical silicon nanowires are obtained. Since the geometrical structure of silicon nanowire is
mainly determined by the initial metallic pattern, the fabrication of metallic nanostructure on a silicon substrate is the key technology
in the MACE process. To obtain highly ordered nanowires with precisely controlled diameter and distribution, the various metal
patterning method such as electron beam lithography, photolithography and nanosphere lithography were suggested. In this study,
we fabricated a highly ordered large area ultraviolet (UV) nanoimprinted etch barrier pattern on an Au catalyst layer with low cost for
MACE process. A silicon nanodot master having 500nm pith, 250nm diameter and 125nm height was prepared by KrF laser scanning
lithography. A transparent flexible mold was UV replicated from the silicon master, and a nanodot barrier pattern was UV imprinted
on a PMMA lift-off layer coated silicon wafer. After RIE process with O
2
gas, the silicon surface was exposed except nanodot barrier
patterned area. An Au layer was deposited on silicon wafer using thermal evaporator and UV imprinted nanodot barrier were lift-
offed with PMMA layer in acetone solution with ultrasonication process. Finally, Au nanohole array was fabricated and MACEed
in hydro fluoride and hydrogen peroxide mixed aqueous solution. Depending on the etching time, 300 – 8000 nm heights silicon
nanowire arrays were successfully demonstrated.
This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of
Korea. (HI14C2687), and the Technology Transfer Development Program (S2334634) funded by the Small and Medium Business
Administration(SMBA, Korea).
Fig. 1 Proposed MACE process with nanoimprinted etch barrier
Biography
Seok-min Kim received his PhD degree from the School of Mechanical Engineering at Yonsei University, Seoul, Republic of Korea. He is currently an associate professor
in the School of Mechanical Engineering at Chung-Ang University, Seoul. His current research interests include design and fabrication of micro/nanostructures for optical
component, gas/bio sensors, micro fluidic chips, and enhanced boiling heat transfer surface.
smkim@cau.ac.krSeok-min Kim et al., Struct Chem Crystallogr Commun, 3:2
DOI: 10.21767/2470-9905-C1-002