Magnetoresistance measurement of unpatterned magnetic tunnel junction wafers by current-in-plane tunneling

Publisher Website
Google Scholar
Abstract
We demonstrate a method for measuringmagnetoresistance(MR) and resistance area product (RA) of unpatterned magnetic tunnel junctionfilm stacks. The RA is measured by making a series of four point probe resistancemeasurements on the surface of an unpatterned wafer at various probe spacings. The key to this technique is in placing the probes at the appropriate spacings, on the order of microns for typical applications. The MR is obtained by repeating the measurement at different magnetic fields. A simple conceptual model and an exact analytical solution in good agreement with experimental data are presented. The current-in-plane tunneling method requires no processing, is fast, and provides reliable data which are reflective of the deposition only.