Improvement of sputtering process for the highest saturation magnetisation of Ni/Al multilayer thin films by Taguchi method

The purpose of this study is to find the optimum sputtered parameters of Ni/Al multilayer thin films for the highest saturation magnetization, hM S . It is the first time that the saturation magnetisation of Ni/Al multilayer films was optimised and thus improved by 7.25 % using Taguchi method. For the application of the method, the most effective parameters: the Ni deposition rate, Ndr; Al deposition rate, Adr; Ni layer thickness, Nlt and Total film thickness, Tft with the level settings were selected as input parameters. And, in order to obtain the film with the hM S value, the hysteresis loops of a series of experiments obtained by Taguchi method were measured with a vibrating sample magnetometer. According to the signal-to-noise ratio and mean response results, the Ndr 3 (0.10 nm/s), Adr 1 (0.02 nm/s), Nlt 3 (45 nm) and Tft 1 (100 nm) were found to be the best conditions to produce the optimum film. Using the optimum parameters with the levels, the hM S value of the optimal film was predicted as 532.6 ± 6.2 emu/cm 3 at 95% confidence interval and experimentally verified as 528.6 emu/cm 3 with a confirmation experiment. The X-ray diffraction and scanning electron microscopy measurements were made for the structural analysis. As it can be seen that the Taguchi results are quite useful for optimising the parameters of the Ni/Al multilayer thin films and therefore can be suggest as a guide for the production of the other multilayer thin films.