Study of DC Characteristics in Reliable 4-T Relay Technology for Ultrafast Low Energy NEM Digital IC’s

Nano-electro-mechanical(NEM) relay technology has been proposed efficiently for ultra-lowpower digital integrated circuit applications [1], [2]. This is because the relay is an ideal switch, and that it exhibits abrupt on/off switching behavior and zero offstate leakage current (IOFF), so that its operating voltage (VDD) can be reduced to be close to zero, in principle. Hence, NEM relay technology can robustly overcome the fundamental energy efficiency limit of CMOS technology [3]. In order to realize this promise, however, relays must have high reliability and low switching voltages. The former requirement has been difficult to achieve because of surface wear and stiction-induced failure. The latter requirement is difficult to achieve with a conventional 3-Terminal (3T) relay design, particularly for highly scaled dimensions [1]. In order to chieve low voltage operation, low pull-in voltage is desired. This is difficult to achieve through layout and process. Longer beams (smaller spring constant) or larger actuation area (higher electrostatic force) can be employed at the expense of larger area. Reducing the air gap