A comparative study on 2D materials with native high-κ oxides for sub-10 nm transistors

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDs) with native high-$\kappa$ oxides have presented a new avenue towards the development of next-generation ultra-scaled field-effect transistors (FETs). These materials have been experimentally shown to form a natively compatible oxide layer with a high dielectric constant, which can help scale down both the transistor size and the supply voltage. We present a material and device performance study into the use of several of these materials – namely HfS${}_2$, HfSe${}_2$, ZrS${}_2$, ZrSe${}_2$ – as channels in sub-10 nm FETs. All four materials exhibit isotropic transport at 10 nm channel length with ON currents over 1000 $\mu$A/$\mu$m but show anisotropic transport and degraded ON currents at 5 nm channel length. In general, the sulfide family excels in terms of subthreshold characteristics at sub-10 nm channel lengths. HfS${}_2$, in particular, surpasses all the other materials in terms of ON currents and subthreshold swing (SS), allowing it to also achieve excellent intrinsic performance. We have identified HfS${}_2$ as a superior material within this TMD family for sub-10 nm FETs.