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 .