Enhanced dielectric deposition on singlelayer MoS2 with low damage using remote N-2 plasma treatment

摘要

Using remote N-2 plasma treatment to promote dielectric deposition on the dangling-bond free MoS2 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 MoS2, with samples undergoing O-2 plasma treatment as a comparison. O-2 plasma treatment causes defects in MoS2 mainly by oxidizing MoS2 along the already defective sites (most likely the flake edges), which results in the layer oxidation of MoS2. In contrast, N-2 plasma causes defects in MoS2 mainly by straining and mechanically distorting the MoS2 layers first. Owing to the relatively strong MoS2-substrate interaction and chemical inertness of MoS2 in N-2 plasma, single-layer MoS2 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 MoS2 in O-2 plasma and the excellent stability of single-layer MoS2 in N-2 plasma, the remote N-2 plasma treatment shows great advantage as surface functionalization to promote dielectric deposition on single-layer MoS2.