An interferometric back focal plane microellipsometry for the determination of optical properties of a slider´s air bearing surface

This paper presents a back focal plane microellipsometer combined with a polarized shifting interferometer. This system is used for the determination of optical phase shift on reflection of a slider´s air bearing surface. These optical properties are essential parameters for the flying height measurements in a HDD manufacturing process. The resulting phase shifting images were processed by using Windowed Fourier filters and phase unwrapping techniques, in order to precisely determine the phase of a back focal plane image. The phase images were then used to determine the optical phase shift on reflection values. The results from an aluminum sample show that the measured optical phase shift on reflection values are comparable to the standard values.