The Effect of Low Energy Ion Implantation on MoS2

Abstract

The use of ultra low energy ion implantation is investigated as a doping method for MoS2. 200 eV Cl and Ar implants at doses between 1 × 1013 and 1 × 1015 cm−2 were introduced into exfoliated MoS2 flakes. XPS results for Cl implants show a decrease in core peak binding energies for Mo3d and S2p with increasing dose, implying a p-doping effect. Implantation of MoS2 device channel regions is shown to reduce the channel's conductivity. However, isolated implantation of the contact region with low doses (1 × 1013 cm−2) of Cl and Ar are shown to improve output characteristics by linearizing the IDS-VDS curves and by increasing current through the device. Cl was shown to be more effective than Ar at increasing the current, implying there is a potential chemical effect as well as damage effect. For higher doses (≥ 1 × 1014 cm−2), the current through the device is reduced with increasing dose for both implant species. This report presents the as-implanted, unannealed results. Post-implantation anneals may be necessary to activate the dopants and fully realize the potential of this doping method.