Magnetic thin films deposition using DC grid-attached magnetron

For deposition of thin magnetic films a modified 2-inch planar magnetron sputtering system with thermally insulated 2 mm permalloy target (75% Ni / 25% Fe) was used. Previously this magnetron sputtering system was used for boron ion beam generation using a self-sputtering mode [1]. Thermal insulation of the NiFe target was provided by use of special pendants with a low heat transfer. To assistance the discharge ignition and the heating of the target above the Curie point, the additional mesh providing the forming of reflective magnetron discharge cell was used. Similar approach but with two attached grids was used for TiN films deposition in [2]. In our case the mesh was made of stainless steel and had 70 % geometrical transparency. For heating of the target the grid was connected to the cathode of the magnetron. The heating occurs at a high operating pressure and supplying the power discharge of about 100 W and a discharge current of 100 mA for a few minutes. After heating of target the discharge current was adjusted to 500 mA (U_dis = 550 V). Operating pressure was reduced to 1.3·10^-3 Torr and the grid was switched from the cathode to the anode potential. Deposition was performed on the glassceramic and GaAs substrates. The substrate temperature does not exceed 100°C. The coating growth rate was about 0.5 μm/min, and the thickness of films was 2 μm.