• Suryavanshi, Saurabh V.
• Mcclellan, Connor J.
• Smithe, Kirby K.
• Yalon, Eilam

Abstract

Semiconductors require stable doping for applications in transistors, optoelectronics, and thermoelectrics. However, this has been challenging for two-dimensional (2D) materials, where existing approaches are either incompatible with conventional semiconductor processing or introduce time-dependent, hysteretic behavior. Here we show that low-temperature (<200 °C) substoichiometric AlOx provides a stable n-doping layer for monolayer MoS2, compatible with circuit integration. This approach achieves carrier densities >2 * 1013 cm-2, sheet resistance as low as 7 kOmega/□, and good contact resistance 480 Omega·mum in transistors from monolayer MoS2 grown by chemical vapor deposition. We also reach record current density of nearly 700 muA/mum (>110 MA/cm2) along this three-atom-thick semiconductor while preserving transistor on/off current ratio >106. The maximum current is ultimately limited by self-heating (SH) and could exceed 1 mA/mum with better device heat sinking. With their 0.1 nA/mum off-current, such doped MoS2 devices approach several low-power transistor metrics required by the international technology roadmap.

Topics

• density
• impedance spectroscopy
• semiconductor
• two-dimensional
• current density
• chemical vapor deposition