Rapid, General-Purpose Patterning of Silicon Nitride Thin Films Under Ambient Conditions for Applications Including Fluid Channel and SERS Substrate Formation.

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 (SiN_x) 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, offeringwith low barriers to rapid useparticular 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. [ABSTRACT FROM AUTHOR]