Titanium nitride sidewall stringer process for lateral nanoelectromechanical relays

This paper reports on lateral nanoelectromechanical (NEM) relays based on variations of a two- or three-mask titanium nitride (TiN) sidewall stringer process. Electrically isolated TiN perimeter beams are fabricated from stringers formed on the inside walls of polysilicon trenches, yielding 200 nm wide TiN fins and 200 nm gaps; these dimensions are 3X smaller than the resolution limit of the optical lithography tool (600 nm) utilized. The reduction in the operating voltage is about a factor of 5 compared to 600 nm wide polysilicon beams. Simple scaling could potentially enable sub-1V operation. Five-terminal NEM relays demonstrate successful switching in both directions over 1000 DC-sweep cycles with low drain bias (100 mV).