Graphene nanoribbon based negative resistance device for ultra-low voltage digital logic applications

Abstract

Negative resistance devices offer opportunities in design of compact and fast analog and digital circuits. However, their implementation in logic applications has been limited due to their small ON current to OFF current ratios (peak to valley ratio). In this paper, a design for a 2-port negative resistance device based on arm-chair graphene nanoribbon is presented. The proposed structure takes advantage of electrostatic doping, and offers high ON current (∼700 μA/μm) as well as ON current to OFF current ratio of more than 105. The effects of several design parameters such as doping profile, gate workfunction, bandgap, and hetero-interface characteristics are investigated to improve the performance of the proposed devices. The proposed device offers high flexibility in terms of the design and optimization, and is suitable for digital logic applications. A complementary logic is developed based on the proposed device, which can be operated down to 200 mV of supply voltage. The complementary logic is used in design of an ultra-compact bi-stable switching static memory cell. Due to its compactness and high drive current, the proposed memory cell can outperform the conventional static random access memory cells in terms of switching speed and power consumption.