Investigation of High Pass-Through-Flux and Sputtering Performance of Ferromagnetic Sputtering Targets

One critical measurable property that determines the strength of the projected magnetic field of the sputter cathode is the so-called “Pass-Through-Flux (PTF)” of the sputter target. Higher and lower PTF values for sputtering targets have been found to directly influence the deposition rate of ferromagnetic materials. In this study, we investigate the effect of varied thermal-mechanical work as well as the resulting microstructure on the PTF of both cobalt and nickel ferromagnetic sputtering targets. A portion of these materials were subjected to recrystallization annealing for different grain sizes. The PTF of the resulting materials was measured both parallel and perpendicular to target surface. In addition, in order to mimic the use of these materials in a sputter tool, the materials were subjected to various magnetic fields to analyze their impact on PTF. The results show that the PTF is significantly influenced by thermomechanical processing, the external magnetic field strength, the thickness of the target, as well as magnetization direction.