Electron irradiation of metal contacts in monolayer MoS$_2$ Field-Effect Transistors.

This work deals with the electron beam irradiation of the Schottky metal contacts in monolayer molybdenum disulfide (MoS$_2$) field-effect transistors (FETs). We show that the exposure of the Ti/Au source/drain leads to an electron beam improves the transistor conductance. We simulate the path of the electrons in the device and show that most of the beam energy is absorbed in the metal contacts. Hence, we propose that the transistor current enhancement is due to thermally induced interfacial reactions that lower the contact Schottky barriers. We also show that the electron beam conditioning of contacts is permanent, while the irradiation of the channel can produce transient effects.