For decades, fabrication of semiconductor
devices has utilized well-established
etching techniques to create complex nanostructures in silicon. Of these, two
of the most common are reactive ion etching in the gaseous phase and
metal-assisted chemical etching (MACE) in the liquid phase. Though these two
methods are highly established and characterized,
there is a surprising scarcity of reports exploring the ability of metallic
films to catalytically enhance the etching of silicon in dry plasmas via a MACE-like mechanism. Here, we
discuss a <u>m</u>etal-<u>a</u>ssisted <u>p</u>lasma <u>e</u>tch (MAPE) performed
using patterned gold films to catalyze
the etching of silicon in an SF<sub>6</sub>/O<sub>2</sub> mixed plasma, selectively
increasing the rate of etching by over 1000%. The degree of enhancement as a
function of Au catalyst configuration and relative oxygen feed concentration is
characterized, along with the catalytic
activities of other common MACE metals including Ag, Pt, and Cu. Finally,
methods of controlling the etch process
are briefly explored to demonstrate the potential for use as a liquid-free
fabrication strategy.
Effect of isopropanol on gold assisted chemical etching of silicon microstructures