Hydrogenated/Fluorinated Phase Borophene Nanoribbons as Nano-Interconnects

Abstract

Density functional theory (DFT) together with non-equilibrium Green's function (NEGF) is used for the theoretical investigation of structural, electronic, and transport properties of zigzag <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$v_{1/6}-30^{\circ }$</tex-math></inline-formula> phase borophene nanoribbons (BNRs). Pristine and fluorinated <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$v_{1/6}-30^{\circ }$</tex-math></inline-formula> phase BNRs are considered for the nanoscale interconnect design. The binding energy computations indicate the improvement in the structural stability of the BNRs with increase in fluorine concentration. The E-k relations reveal the hydrogen (H) and fluorine (F) passivated BNRs are metallic. The quantum transport properties are evaluated using the two-probe geometry method. The current-voltage (I-V) behavior of the considered BNR devices are linear with applied bias. Further, interconnect distributed model is explored and the dynamical parameters are evaluated. The Fermi velocity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$v_{f}$</tex-math></inline-formula> ) is measured to be highest for the H and F passivated BNR (F-BNR-H) of about 3.784 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\times 10^{4}$</tex-math></inline-formula> m/s. The dynamic parameters for the nanoscale interconnects are improved upon fluorinating the BNRs. The calculated values of quantum resistance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R_{Q}$</tex-math></inline-formula> ), quantum capacitance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$C_{Q}$</tex-math></inline-formula> ) and kinetic inductance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$L_{K}$</tex-math></inline-formula> ) for F-BNR-H are 1.845 K <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula> , 28.61 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$nF/m$</tex-math></inline-formula> , and 24.38 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$nH/\mu m$</tex-math></inline-formula> , respectively. Further, F-BNR-H device is found to have relatively lower delay from delay calculations. The stability and frequency analysis determine that the F-BNR-H has superior stability and bandwidth as compared to Cu interconnects. The interconnect performance is found to reduce with edge roughness and line parasitic effects. These theoretical findings suggest the fluorinated BNRs can be potentially used as the metal interconnect at nanoscale dimensions.