Preparation Of Titanium Nitride Thin Films By Magnetron Sputtering And Investigation On The Structure And Conductivity Of The Films

Titanium nitride thin films were prepared by DC magnetron reactive sputtering on p-type Si(111)substrates.The structure and property of sputtering deposited thin film are influenced by many process factors,such as sputtering current,flow rate of nitrogen,total deposition pressure,substrate temperature and substrate bias.In this paper,the influence of the four factors,sputtering current,flow rate of nitrogen, deposition pressure,and substrate temperature on the structure and property of TiN_x thin films were investigated.The phase of TiN_x thin films is analyzed by X-ray diffraction(XRD).The surface morphologies of the thin films were examined by atomic force microscopy(AFM).The thickness and sheet resistance of TiN_x thin films were measured by a surface profilometer and four-probe resistivity meter, respectively.It is shown that the main component of the TiN_x thin films prepared under total deposition pressure 1.0Pa,the flow rate of Ar 15.0 sccm,and substrate temperature 270℃is Ti₂N with(110)prefered orientation when sputtering current and the flow rate of N₂ were changed.The thin films show smooth surface,fine particle mean size.The resistivity of TiN_x thin films increases as sputtering current increases.In particular,the resistivity of TiN_x thin films is not a monotone function of the flow rate of N₂ and exists a minimal value at a special value of the flow rate of N₂.The main component of the TiN_x thin films prepared under the flow rate of Ar 30.0 sccm,the flow rate of N₂ 2.5sccm,and the sputtering current 0.35A is TiN when total deposition pressure and substrate temperature were changed.The TiN_x thin films have(200)prefered orientation when the films are thin and(111)prefered orientation when the films are thick.The thin films show rough surface,large particle mean size. The two technical parameters have obviously influence on the conductivity of TiN_x thin films.The resistivity of TiN_x thin films decreases as deposition total pressure decreases and substrate temperature increases.By analying the data of experiment,we find the optimized parameters as follows: the flow rate of Ar 30.0 sccm,the flow rate of N₂ 2.5sccm,the sputtering current 0.35A,total deposition pressure 0.3Pa and substrate temperature 330℃.The resistivity of TiN_x thin films prepared under the condition listed above is 33.7μΩ·cm, which is near to that of bulk TiN.