Plasma Characteristics And Performances Of TiN Films Prepared By Superimposed HiPIMS And MF

High power impulse magnetron sputtering(HiPIMS)has the advantages of high peak power density,high target ionization,and dense microstructure of deposited films.However,the method has some disadvantages,such as low deposition rate and easy arcing.Aiming at the drawbacks of HiPIMS,this work attempeted to construct the superimposition power system by using the power supply design idea of middle frequency(MF)and HiPIMS(superimposed HiPIMS and MF).The effects of the MF duration and power variation on the discharge and plasma characteristics of superimposition power supply and the microstructure and performances of the TiN films were studied in detail.The main conclusions are as follows:(1)With the increase of MF duration,the HiPIMS pulse peak power density decreased from 686 W/cm~2 to 460 W/cm~2,decreased by 32.9%.And the ionization rate decreased from 0.39 to 0.10,decreased by 74.3%.With the increase of MF power,the HiPIMS pulse peak power density fluctuated in the range of 477-501 W/cm~2.And the ionization rate increased from 0.18 to 0.22.The HiPIMS pulse peak power density and the ionization rate were more sensitive to the change of MF duration than to MF power.(2)Component analysis showed that the Ti content of TiN films increased significantly with the increase of MF duration and power.XRD analysis showed that the crystal orientation of TiN films deposited by HiPIMS and superimposed HiPIMS-MF was changed obviously.The diffraction peak of TiN films(111)was the strongest,and with the increase of MF duration and power,the diffraction peak strength of TiN films,which were deposited by superimposed HiPIMS-MF,(200)was decreased and(111)was increased.(3)The analysis of morphology and structure of TiN films showed that the surface of TiN films deposited by HiPIMS and superimposed HiPIMS-MF was granular,and the particle size increased with the increase of MF duration and power.The columnar microstructure of TiN films deposited by DC was not dense,and there were white gaps in the TEM image.The HiPIMS model had no defect in columnar microstructure,and the columnar morphology disappeared gradually with the increase of MF duration and power,and the TiN films deposited by HiPIMS and superimposed HiPIMS-MF was dense and defect-free in TEM images.(4)Performances test results showed that with the increase of MF duration,the hardness of TiN films decreased from 31.0 GPa to 21.2 GPa,decreased by 31.6%.And the elastic modulus decreased from 312 GPa to 231 GPa,decreased by 30%.With the increase of MF power,the hardness of TiN films fluctuated within the range of24.7-26.2 GPa,and the elastic modulus was reduced from 286 GPa to 235 GPa,down by 17.8%.The hardness of TiN films was mainly affected by microstructure and density,and the elastic modulus was mainly influenced by composition and density.When the composition was close,the density had a significant effect on the elastic modulus,and when the density was close,the influence of the composition on the elastic modulus was significant.The adhesion of TiN films was affected by the microstructure,density and residual stress of TiN films,only the best comprehensive performances can got the best adhesion quality.