TY - JOUR
T1 - Self-aligned formation of nano-holes to arrayed micro glass tubes
AU - Sato, Hirotaka
AU - Yamaguchi, Takuya
AU - Isobe, Tetsuhiko
AU - Homma, Takayuki
AU - Shoji, Shuichi
PY - 2007/11/20
Y1 - 2007/11/20
N2 - Microreactors and micro-fluidic devices require micro-tube structures to reserve and manipulate extremely small volume of liquid specimen, and nano-hole on the micro-tube is useful for its injection, aspiration and filtration, etc. In the present study, we attempted to develop a precise etching process to form nano-hole to the edge part of the micro glass tube by controlling SiO2 etching conditions with diluted aqueous HF solution. The arrayed micro-glass-tubes were fabricated by electrochemical etching of Si wafer followed by wet-thermal oxidation. The bottoms of arrayed micro-glass-tubes were exposed from Si wafer, which possessed pyramid-shape edges. The etching with optimized concentration of HF formed uniform nano-holes only at every bottom edge, indicating self-alignment of the etching process. The diameter of the nano-holes was controllable in the range of ca. 100-500 nm by adjusting the immersion duration and thickness of the glass tube. Nonlinear diffusion of fluoride species to the bottom edges could be the origin of the self-aligned formation of nano-holes at the bottom edges.
AB - Microreactors and micro-fluidic devices require micro-tube structures to reserve and manipulate extremely small volume of liquid specimen, and nano-hole on the micro-tube is useful for its injection, aspiration and filtration, etc. In the present study, we attempted to develop a precise etching process to form nano-hole to the edge part of the micro glass tube by controlling SiO2 etching conditions with diluted aqueous HF solution. The arrayed micro-glass-tubes were fabricated by electrochemical etching of Si wafer followed by wet-thermal oxidation. The bottoms of arrayed micro-glass-tubes were exposed from Si wafer, which possessed pyramid-shape edges. The etching with optimized concentration of HF formed uniform nano-holes only at every bottom edge, indicating self-alignment of the etching process. The diameter of the nano-holes was controllable in the range of ca. 100-500 nm by adjusting the immersion duration and thickness of the glass tube. Nonlinear diffusion of fluoride species to the bottom edges could be the origin of the self-aligned formation of nano-holes at the bottom edges.
KW - Arrayed microstructure
KW - Etching
KW - Maskless nanofabrication
KW - Microreactor
KW - Silicon micromachining
UR - http://www.scopus.com/inward/record.url?scp=34548579193&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548579193&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2007.02.075
DO - 10.1016/j.electacta.2007.02.075
M3 - Article
AN - SCOPUS:34548579193
VL - 53
SP - 200
EP - 204
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
IS - 1
ER -