Enhanced dielectric deposition on single-layer MoS 2 with low damage using remote N 2 plasma treatment.

Using remote N ₂ plasma treatment to promote dielectric deposition on the dangling-bond free MoS ₂ is explored for the first time. The N ₂ plasma induced damages are systematically studied by the defect-sensitive acoustic-phonon Raman of single-layer MoS ₂ , with samples undergoing O ₂ plasma treatment as a comparison. O ₂ plasma treatment causes defects in MoS ₂ mainly by oxidizing MoS ₂ along the already defective sites (most likely the flake edges), which results in the layer oxidation of MoS ₂ . In contrast, N ₂ plasma causes defects in MoS ₂ mainly by straining and mechanically distorting the MoS ₂ layers first. Owing to the relatively strong MoS ₂ -substrate interaction and chemical inertness of MoS ₂ in N ₂ plasma, single-layer MoS ₂ shows great stability in N ₂ plasma and only stable point defects are introduced after long-duration N ₂ plasma exposure. Considering the enormous vulnerability of single-layer MoS ₂ in O ₂ plasma and the excellent stability of single-layer MoS ₂ in N ₂ plasma, the remote N ₂ plasma treatment shows great advantage as surface functionalization to promote dielectric deposition on single-layer MoS ₂ .