Complementary Arranged Graphene Nanoribbon-based Boolean Gates

With CMOS feature size heading towards atomic dimensions, unjustifiable static power, reliability, and economic implications are exacerbating, prompting for research on new materials, devices, and/or computation paradigms. Within this context, Graphene Nanorib-bons (GNRs), owing to graphene's excellent electronic properties, may serve as basic blocks for carbon-based nanoelectronics. In this paper we build upon the fact that GNR behaviour can be controlled according to some desired functionality via top/back gate contacts and propose to combine GNRs with complementary functionalities to construct Boolean gates. To this end, we introduce a generic GNR-based Boolean gate structure, composed of two GNRs, i.e., a pull-up GNR performing the gate Boolean function and a pull-down GNR performing the inverted Boolean function. Subsequently, by properly adjusting GNRs' dimensions and topology, we design 2-input AND, NAND, and XOR graphene-based Boolean gates, as well as 1-input gates, i.e., inverter and buffer. Our SPICE simulations indicate that the proposed gates exhibit a smaller propagation delay, from 23% for the XOR gate to 6× for the AND gate, and 2 orders of magnitude smaller power consumption, when compared with 7 nm CMOS based counterparts, while requiring a 1 to 2 orders of magnitude smaller active area footprint. These results clearly indicate that GNR-based gates have great potential as basic building blocks for future beyond CMOS energy effective nanoscale circuits.