A highly sensitive and broadband method of obtaining the permeability of magnetic film without limitations in sample size was developed based on the high frequency impedance of microstrip meander probe and magnetic film. The probe (5.6 mm × 5 mm, 2 turns) was scanned in the vicinity of a CoNbZr thin film (50 × 50 mm, 0.1 μm thick), and the permeability was optimized by Newton-Raphson method in a frequency range of 10 MHz - 8 GHz. The measured values roughly corresponded to theoretical values based on the Landau-Lifshitz-Gilbert equation and eddy current generation. The proposed method shows promise for measuring the permeability of wafer-sized samples in-line because it is not restricted by size limitations.
- Magnetic thin film
- Meander line