Time-domain AC characterization of silicon carbide (SiC) nanoelectromechanical switches toward high-speed operations

Abstract

We report an experimental study on AC measurements of contact-mode switches based on silicon carbide (SiC) nanoelectromechanical systems (NEMS). We describe the development of circuits and measurement techniques for recording long cycles of AC switching characteristics of SiC NEMS featured by ultrasmall device movable volumes (at ~1μm 3 level) and contact areas (only ~0.01-0.1μm 2 ), and challenging contact resistances (can be from ~10kΩ to ~100MΩ). We perform time-domain AC characterization of SiC NEMS switches with operating speeds up to 1kHz and high on/off current ratios of ~10 6 . For multiple devices, we have recorded the complete time evolution of AC switching data traces of >10 6 cycles at 1kHz, without failure in ambient air. Beyond these long cycles the devices are still alive, which demands even higher-speed, accelerated AC measurements for long-lifetime recording.

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

“…The NEM switch components can be produced from a wide range of nanostructures (e.g., thin films [ 5 – 7 ], nanobundles [ 8 ], nanowires [ 9 – 14 ], nanotubes [ 15 – 16 ]) fabricated from different materials (e.g., metals [ 17 – 19 ], semiconductors [ 9 – 10 20 – 23 ], carbon allotropes, including graphene [ 24 – 31 ] and carbon nanotubes [ 12 , 15 – 16 32 – 37 ]). With a proper choice of material and architecture, NEM switches can withstand relatively high radiation levels and extreme temperatures [ 19 , 25 , 38 – 39 ], highlighting their potential for applications in harsh environments.…”

“…The fabrication can be based either on entirely top-down, or on a combination of top-down, bottom-up and nanomanipulation approaches. The top-down approach involves lithography, etching and coating technologies to fabricate device structures from bulk materials or thin films [ 7 , 19 , 23 , 39 , 47 – 50 ]. The combined approach of fabricating NEM switches requires subsequent transfer and alignment of synthesized nanostructures (nanowires, nanotubes, nanorods, graphene) with a good uniformity and desired properties.…”

Silicon carbide (SiC) nanoelectromechanical switches and logic gates with long cycles and robust performance in ambient air and at high temperature

“…The green symbol in Fig. 13a is the latest measured number of cycles, where the SiC NEMS switch operates in a periodic contacting mode at high speed, demonstrating very long 'cold' switching cycles >10 10 . These results suggest that the intrinsic lifetimes of the SiC NEMS switches are yet to be measured and precisely tested in future high-speed measurements.…”

“…(ii) Most truly nanoscale contact-mode NEMS switches known to date (often based on various nanowires, cantilevers and nanotubes) still suffer from very short lifetimes. In this regard, SiC is a special material that offers a unique and promising opportunity toward long lifetimes in NEMS contact-mode switches and circuits [6][7][8][9][10]. In this work, we demonstrate real-time recorded long cycles of SiC NEMS switches that exhibit the best lifetimes to our best knowledge, among various NEMS switches reported lately.…”

“…Interrogating NEMS switches at higher speed has been particularly challenging due to the rapidly time-varying impedance during the switching transient process [10]. Fig.…”