Rapid, General-Purpose Patterning of Silicon Nitride
Thin Films Under Ambient Conditions for Applications Including Fluid
Channel and SERS Substrate Formation
posted on 2020-03-17, 12:03authored byBrian
S. Sheetz, Y.M. Nuwan D.Y. Bandara, Benjamin Rickson, Michael Auten, Jason R. Dwyer
Silicon
nitride thin films are useful as etch-stop masks in micro- and nanofabrication.
As structural elements, they are prevalent in applications as diverse
as single-molecule sensing, transmission electron microscopy, ultrafast
spectroscopy, superfluidity studies, and high flux liquid filtering.
A hand-held “flameless” Tesla-coil lighter was used
to create vias through 200 nm silicon nitride (SiNx) films coating silicon wafers. The processing allowed spatially
directed KOH etching of the underlying Si. Patterning could be achieved
with a hard mask or rastering of the spatially confined discharge,
offeringwith low barriers to rapid useparticular capabilities
that might otherwise be out of reach to researchers without access
to conventional, instrumentation-intensive micro- and nanofabrication
workflows. General patterning capabilities were demonstrated, followed
by the formation of a trench suitable for microfluidic applications.
Finally, a discharge-treated thin film surface was sputter coated
with gold to create a surface enhanced Raman spectroscopy (SERS) substrate
that was then used to detect a test analyte at ppm concentration.