Graphene-Based Interconnects on Hexagonal Boron Nitride Substrate

Abstract

We demonstrated graphene interconnects on layered insulator-hexagonal boron nitride ( h-BN). Performance metrics are compared among three material systems: CVD graphene on h-BN, CVD graphene on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , and exfoliated graphene on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . CVD graphene on h-BN shows approximately 19 times and 8 times improved conductivity as compared with CVD graphene on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and exfoliated graphene on SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , respectively. For graphene on h-BN, an ultrahigh carrier mobility (~ 15 000 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s at a carrier density of 1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ) is observed. The breakdown power density is much increased, attributed to the higher thermal conductivity of h-BN (than that of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) that facilitates heat dissipation. Electrical annealing reduces graphene sheet resistance. Unlike the case for SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> substrate, the absence of positive shift of Dirac point could be due to the interface-state-free nature of h-BN substrate. The research suggests that h-BN could be used as an alternative substrate material for graphene-based interconnects, overcoming performance limit and reliability issues caused by the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> substrate.