Effect of N2 flow rate on structure and property of ZrNbAlNx multilayer films deposited by magnetron sputtering

Deposition property and microstructure evolution of nano-scaled ZrNbAlNx multilayer films, which present a periodic modulation structure of ZrNx/AlNx/ZrNx/NbNx with different N atomic concentration, deposited using a reactive unbalanced magnetron sputtering system was investigated by varying N2 flow rate. Multilayer films were characterized using X-ray diffraction, Scanning electron microscope, Transmission electron microscope, Laser Raman spectrometer and nano-indentation tester. The experimental results show that the nano-scaled multilayer film displays a columnar growth at N2 flow rate of 4 sccm and an un-columnar deposition at N2 flow rate of 33 sccm. The increase in N2 flow rate leads to increase of N atomic concentration and decrease of Zr atomic concentration. Microstructure of multilayer films indicates a variation from close-packed hexagonal structure with (1 0 1) preferred orientation to faced cubic structure with (1 1 1) preferred orientation. The Raman spectrums position presents a shift corresponding to microstructure evolution of multilayer films. Maximum micro-hardness value of multilayer film is 22 GPa at N2 flow rate of 27.5 sccm.

► A novelty ZrNbAlNx multilayer film with different N2 flow rate was deposited.
► Chemical composition and property of multilayer films were affected by N2 flow rate.
► Vickers hardness value shows a typical variation with the increase in N2 flow rate.