Sub-200 Ω·µm Alloyed Contacts to Synthetic Monolayer MoS2
Aravindh Kumar, Kirstin Schauble, Kathryn M. Neilson, Alvin Tang, Pranav Ramesh, H.‐S. Philip Wong, Eric Pop, Krishna C. Saraswat
Abstract
While two-dimensional (2D) semiconductors like Mos2 are promising for applications in nanoscale transistors, their performance is limited by their contacts. Here, we report contact resistance as low as 190 Ω·µm for In/Au alloy and 270 Ω·µmfor Sn/ Au alloy contacts to monolayer Mos2, which are among the best reported to date. We perform a statistical study of 720 transistors comparing different contact schemes, re-vealing both the ‘best’ and ‘average’ alloyed contacts, as well as their distribution, for the first time. Material characterization confirms the metal contacts are not damaging Mos2 and that the contact metal stacks are alloyed. This combines the benefits of a metal with low work function and low melting point with those of a stable noble metal, resulting in ~450°C temperature tolerance compatible with back-end processing.