Integrated 4-terminal single-contact nanoelectromechanical relays implemented in a silicon-on-insulator foundry process

Abstract

Silicon 4-T NEM relays, patterned in front-end-of-line processing and monolithically integrated with back-end-of-line metallic interconnects manufactured in a commercial foundry platform.

Digital Nanoelectromechanical Non-Volatile Memory Cell

“…By scaling and reducing the critical dimensions to sub micron features, we have successfully fabricated and characterised a fully mechanical memory cell that can be driven using a digital access pattern and does not require transistors for read and write access, the first such demonstration. The scaling has reduced the cell footprint by a factor of 8.5 (see Table I), but the overall area can be further reduced by a significant amount with a multi-layer interconnect stack, possible with a heterogeneous integration approach [21] or by fabricating the relays in a front-endof-line process [22], and more aggressive scaling. While all operating voltages were reduced, the reprogramming voltage remained relatively high, a consequence of using gold as a contact material, as it increases the surface adhesion force [18], [23].…”

“…By using a better contact material with a lower surface energy, such as a carbon-based material [17], [24], the reprogramming voltage can be further reduced. Moreover, further reductions in the actuation airgaps and hinge width have potential to reduce the voltages to the sub 5 V regime (eg: see [9], [22]) needed for compatibility with electronics used at the edge of the network. This work has shown the potential for building NEM relay-based embedded non-volatile memories with a digital access protocol for such applications.…”