Capacitive and ohmic RF NEMS switches based on vertical carbon nanotubes

Abstract

The objective is to demonstrate a reproducible carbon nanotube (CNT)-based technology for radio frequency (RF) switch working in the range of 40–60 GHz and fulfilling the specifications: low losses, high isolation, and an operating voltage below 30 V. The first processed component had an operating voltage of 14 V for an ohmic contact in a Nano-Electro Mechanical System (NEMS) tweezer design. This result is confirmed by theory with an operating voltage of 13 V. A capacitive-contact NEMS is also developed using multi-walled CNTs (MWCNTs) coated with a SiO2 dielectric layer deposited by electron beam induced deposition method (EBID). High Frequency Simulation Software (HFSS) RF-simulation on an innovative NEMS geometry shows encouraging results with transmission ratios between “on” state and “off” state up to 34% for ohmic-contact switch and 25% for a capacitive-contact switch.