Growth characteristics of MoS2 coatings prepared by unbalanced bipolar DC magnetron sputtering

Abstract

MoS2 coatings were prepared by unbalanced bipolar DC magnetron sputtering under different argon pressures and for different deposition times, and the structure and morphology of MoS2 coatings were determined and observed respectively by X-ray diffractometry and scanning electron microscopy. The results show that at lower argon pressures of 0.15 Pa and 0.40 Pa, MoS2 coatings are formed with the (002) basal plane parallel to the surface, whereas the coating deposited at the argon pressure above 0.60 Pa has the (002) basal plane perpendicular to the surface. Two stages can be classified for the formation of MoS2 coating. At the initial stage of coating formation, the (002) basal plane with S-Mo-S layer structure grows on the substrate whatever the argon pressure is. And then the coating under 0.40 Pa argon pressure still grows with (002) laminate structure, but the coatings under 0. 88 Pa and 1.60 Pa argon pressures turn to grow with the mixed basal and edge orientations. The morphology and structure of MoS2 coatings are highly related to their growth rate and the energy of sputtered particles.