Boolean circuit design using emerging tunneling devices

Abstract

Novel device technologies are exceedingly under investigation for the sub-10-nm era. Some tunneling devices employing 2-D materials have shown the potential for low-voltage operation, promising energy efficient digital circuits and systems. Interestingly, certain emerging tunneling devices such as SymFETs and BiSFETs exhibit an I-V characteristic different from that of MOSFETs. In this paper, the design of Boolean gates with SymFETs is studied. We show that the negative differential resistance (NDR) behavior of the transistors leads to hysteresis in inverters and buffers, and can be used to build simple Schmitttriggers. It can also by used in designing new pseudo-SymFET loads for circuits similar to all-n-type or dynamic logic. We demonstrate the feasibility of building NAND, NOR, IMPLY, and MAJORITY gates with fewer transistors when compared with static CMOS designs. Benchmarking efforts show that SymFETs are an attractive choice for applications that demand low power and have moderate speed requirements, and demonstrate better dynamic energy efficiency than CMOS circuits; but one challenge for SymFET circuits is relatively larger leakage currents.