The Microstructure And Mechanical Properties Of Titanium Nitride Films Deposited By High Power Pulsed Magnetron Sputtering(HPPMS) At Different Work Pressure And Target Magnetic Field Strength

Owing to its extreme hardness,dense structure,high adhesion strength,and good thermal conductivity,Titanium nitride(TiN)deposited by high power pulsed magnetron sputtering(HPPMS)has been applied in various fields.But there are three disadvantages(big residual stress,low deposition rate and film toughness)about TiN films,which limits its application fields.In order to reduce film residual stress and improve deposition rate and film toughness,in this paper,we design to change deposition pressure to control ion energy so as to reduce film residual stress and change target magnetic field to increase the amount of sputtering species before substrate.Furthermore,TiN multilayer film design is used to improve film toughness.In this paper,TiN films were fabricated by HPPMS at different deposition pressure(0.2,1.0,and 2.0 Pa)and magnetic field strength(40 and 115 mT).The plasma and ion energy in the HPPMS discharge were diagnosed respectively by optical emission spectroscopy and self-regulating ion energy device.The effects of deposition pressure and magnetic field strength on film deposition rate,residual stress,and mechanical properties were also investigated.In order to solve low toughness of TiN film,TiN films with different hardness and stress were deposited alternately on substrate by,changing deposition pressure(0.2 Pa,2.0 Pa)alternately,which realized the fabrication of TiN multilayer film.And film toughness was studied.Research results show that increasing deposition pressure can reduce ion energy,which resulted in a sharp decrease in residual stress(from 8.5 to 0.8 GPa at 40 mT magnetic field strength)and a significant increase in the adhesion strength of TiN films.Decreasing magnetic field strength(from 115 mT to 40 mT)lead to a significant increase in the Ti+/Ti ratio of the substrate,by a factor of?3,and a large increase in the deposition rate,especially by a factor of?5.5.The lower magnetic field strength(40 mT)also resulted in a preferred and stronger(111)orientation,greater film hardness,and better adhesion strength of the TiN films.TiN films with low residual stress and a high deposition rate,hardness and adhesion strength were obtained at lower magnetic field strength(40 mT)and higher deposition pressure(2.0 Pa).And compared with single TiN film,TiN multilayer film deposited by changing deposition pressure(0.2 Pa,2.0 Pa)alternately can improve film toughness greatly.