Laterally Actuated Platinum-Coated Polysilicon NEM Relays

Abstract

Laterally actuated polycrystalline silicon nanoelectromechanical (NEM) relays with enhanced electrical properties are presented. Due to surface oxidation of polysilicon in room ambient conditions, the relays have a high contact resistance (> 1 GΩ) that requires high drain bias (3-5 V) to break through. The addition of a platinum sidewall coating reduces the on-resistance and the required drain bias to as low as 3 kΩ and 0.1 V, respectively. The platinum coating's stability is demonstrated by two tests: first, a contact-and-hold test where the relay passes current (~1μA) for up to 155 min and, second, a hot cycling test where the relay survives for over 10 8 cycles . The NEMS relays are simulated using finite-element analysis, and the models are verified against experimental tests. Furthermore, the relays are configured and tested as a 2 : 1 multiplexer to show their potential as a digital logic component.