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Photoassisted Electrochemical Micropatterning of Gold Film
journal contribution
posted on 2019-06-25, 00:00 authored by Shasha Liu, Tinglian Yuan, Wei Wei, Hua Su, Wei WangElectrochemical
etching is a powerful and popular method for fabricating
micropatterns on metal substrates for use in electronic devices, electrochemical
sensors, and plasmonic substrates. In order to achieve micropatterning,
either a prepatterned insulating layer (mask) or a scanning microelectrode
is often required to selectively trigger electrochemical etching at
the desired locations. In the present work, we employed a well-focused
light beam to enable the photoassisted electrochemical etching of
gold film with a spatial resolution close to the optical diffraction
limit (∼300 nm). It was found that the simultaneous application
of light irradiation and appropriate potential were critical for the
oxidative dissolution (i.e., etching) of gold to occur. Superior controllability
of light beam allowed for the direct-write micropatterning without
the need of mask or probe. Etching kinetics and mechanism were also
studied by monitoring the dynamic evolution of optical transparency
with a conventional transmission bright-field microscope, together
with characterizations on the as-obtained patterns with atomic force
microscopy and electron microscopy. This study is anticipated to contribute
a feasible method for the micropatterning of gold film with implications
for nanoelectronics and electrochemical sensors.