Design and analysis of hybrid NEMS-CMOS circuits for ultra low-power applications

Abstract

Integration of nano-electro-mechanical switches (NEMS) with CMOS technology has been proposed to exploit both near zero-leakage characteristics of NEMS devices along with high ON current of CMOS transistors. The feasibility of integration of NEMS switches into a CMOS process is illustrated by a practical process flow. Moreover, codesign of hybrid NEMS-CMOS as low power dynamic OR gates, SRAM cells, and sleep transistors is explored. Simulation results indicate that such hybrid dynamic OR gates can achieve 60-80% lower switching power and almost zero leakage power consumption with minor delay penalty. However, the hybrid gate outperforms its CMOS counterpart both in terms of delay and switching power consumption with increase in fan-in beyond 12. Additionally, it is shown that the proposed hybrid SRAM cell can achieve almost 8X lower standby leakage power consumption with only minor noise margin and latency cost. Finally, application of NEMS devices as sleep transistors results in upto three orders of magnitude lower OFF current with negligible performance degradation as compared to CMOS sleep switches.

Peranti Suis Sistem Nanoelektromekanikal (NEMS) Berunsurkan Grafin dan Tiub Nano Karbon (CNT)

“…Prestasi cemerlang yang dicapai oleh sebilangan kecil suis NEM telah mendapat tempat dalam pelan halatuju ITRS sebagai pengganti berpotensi atau hibrid yang melengkapkan peranti CMOS konvensional kerana beberapa kelebihan seperti penggunaan komponen yang lebih kecil dalam peranti seterusnya mengurangkan pensuisan dinamik sebanyak 60% telah dilaporkan untuk hibrid get OR (Dadgour & Banerjee 2007). Selain itu, hanya dua suis NEM digunakan untuk membuat get empat-terminal XOR, sedangkan get logik ini memerlukan sekurangkurangnya sepuluh transistor CMOS untuk membuatnya.…”

“…Oleh kerana saiz peranti semikonduktor dikurangkan kepada beberapa puluhan nanometer dan permintaan untuk lebih banyak aplikasi terus meningkat, strategi lain amat diperlukan. Sebagai contoh, suis NEM adalah salah satu calon untuk menyelesaikan isu penggunaan kuasa yang tinggi dalam peranti complementary metal-oxide semiconductor (CMOS) sekiranya saiz peranti dikurangkan kepada saiz nano (Dadgour & Banerjee 2007;Peschot et al 2015).…”

An Energy-Efficient Design Paradigm for a Memory Cell Based on Novel Nanoelectromechanical Switches

“…The subthreshold leakage is mainly affected by the subthreshold swing (S) of a device, which is defined as the amount of gate voltage reduction to reduce the subthreshold current by one decade (S = dVgs/dlogId) [3]. For bulk CMOS, the subthreshold swing has a substantially lower limit of 60 mV/decade, which leads to a large increase in the power density [4]. This limitation prevents manufacturers from fabricating smaller devices and forces them to look for alternative solutions targeting higher performance and efficiency.…”

“…In spite of the large mechanical delay and limited number of reliable cycles, NEMs have been useful for a wide range of applications such as FPGAs (used as programmable routing switches) [8], adders [9], flip-flops [10], memories [4,11], DACs [9], and ADCs [9], where the long switching time and limited number of hits are not important issues. Most of the mentioned circuits use the benefits of combining NEMs and CMOS technology in order to highlight the advantage points of each technology and alleviate the disadvantages to achieve low-power and high-performance operation for some critical components.…”

Advanced NEMS-based power management for 3D Stacked Integrated Circuits

“…Various enhancements for MTCMOS technologies have been proposed to suppress the sleep transistor leakage current [6]. Moreover it has been suggested that nano-electromechanical FETs (NEM-FETs) are viable candidates to replace the High-V t FET based sleep transistor [7], [8]. However, although fabrication feasibility of simple hybrid CMOS-NEMS circuits has been reported in [9], further technological enhancements are needed for such an approach to become a potentially viable industrial solution.…”