High-Performance Monolayer BeN2 Transistors With Ultrahigh On-State Current: A DFT Coupled With NEGF Study

Abstract

Conventional field-effect transistors (FETs) based on silicon downscaling are approaching physical limits, and thus, it is urgent to explore additional novel solutions to address this issue. The 2-D semiconductors have unique advantages as the channel material and provide a promising prospect for high-performance FETs in the post-Moore era. In this work, a new 2-D semiconductor, monolayer BeN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , is studied for the FET performance limits through first-principle quantum-transport simulations. Monolayer BeN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> exhibits a graphene-like planar structure with a direct bandgap of 1.3 eV. Transfer characteristics of sub-10-nm BeN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> FETs are thoroughly assessed through scaling gate length. In particular, 2-D BeN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> FETs with 10-nm gate present the ultrahigh ON-state current above <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4500\,\, \mu \text{A}/\mu \text{m}$ </tex-math></inline-formula> for high-performance applications. Also, we realize the significant reduction of gate length (only 2.5 nm) against the International Technology Roadmap for Semiconductors (ITRS) requirements through introducing underlap structures. In addition, the performance of single devices based on monolayer BeN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is evaluated and compared with some of the recently proposed 2-D devices.