Tailoring the electronic properties of nickel silicide by interfacial modification

Abstract

Tailoring the microstructures to obtain metal silicide with low resistance and silicide monophase structure is a critical issue in integrated circuits manufacturing. In this work, the effect of introducing Pt insertion on the electronic properties and microstructure of the 9 nm NiPt thin film deposited by magnetron sputtering was studied. By introducing a thin Pt interlayer between the NiPt film and the substrate Si, the sheet resistance of the film can be effectively tuned. The results show that the sheet resistance of the film decreased from 27.6 to 14 Ω/sq, indicating that electrical performance has been enhanced about 1 times with Pt insertion introduced. The results show that the sheet resistance of the NiPt film with Pt insertion was lower and the phase composition of NiPt and Si presents a lower resistance NiSi phase than that of the NiPt without Pt insertion, and the sheet resistance of the film can be further reduced and the NiSi phase structure can be optimized. X-ray diffraction result shows that the phase composition of the NiPt film with Pt insertion presents a lower resistance NiSi phase than that of the NiPt without Pt insertion. Moreover, x-ray electron spectroscopy reveals that Pt insertion can reduce the diffusion of Ni into silicon effectively, which is beneficial to the formation of the monophase structure. In addition, x-ray reflectivity analysis showed that the Pt insertion further improved and modified the interface structure of nickel silicide, resulting in a smoother interface and improved electrical properties. These findings provide useful guidance for tuning the properties of the nickel silicide and also clarify the interface effect in the metal silicide materials.