CMOS-NEM relay based on tungsten VIA layer

A CMOS-NEM tungsten relay based on a 3-T configuration for logic applications is presented. The relay is integrated monolithically in the BEOL of a standard CMOS technology (AMS 0.35 μm) using the tungsten VIA3 layer. The relay is designed and fabricated during the CMOS process and released by a one-step mask-less wet etching. The measured devices show an essentially zero leakage current and a subthreshold slope less than 5 mV/decade with a 10⁴ ratio between on-off current, although they exhibit a high contact resistance (~ 10⁸ Ω). A cycling test was carried out up to 1800 cycles in ambient conditions. Throughout this test, the switch shows great endurance. Finally, the frequency response was also measured.