Lowering the Schottky Barrier Height by Titanium Contact for High-Drain Current in Mono-layer MoS2 Transistor

Abstract

This paper investigates quantum mechanical effects on surface potential and threshold voltage in a two-dimensional molybdenum disulfide (MoS $$_{2}$$ ) based transistor. Drain current improvement occurs as a result of the low work function for metal Ti and electron affinity of MoS $$_{2}$$ , thereby reducing the Schottky barrier height (SBH). The titanium (Ti) contact introduced into the mono-layer MoS $$_{2}$$ helps in obtaining lower contact resistance and improved drain current due to the lowering of SBH. An analytical model is proposed for evaluating various device parameters such as surface potential, threshold voltage, contact resistance, mobility, and drain current. This model provides useful aspects for understanding the physics of quantum mechanical effects. Compared to other conventional devices, this transistor incorporates Ti, a low work function metal, in the contact region, producing better current drive and lower contact resistance values. A positive Schottky barrier is noticed between the mono-layer MoS $$_{2}$$ and the Ti metal. Compared to other high function metals, the proposed device displayed about 11% improvement in current drive and 8% less contact resistance. By attaining an enhanced carrier injection and decreased contact resistance, this device serves as a suitable prospect for low-power applications.