Barrier layers for anisotropic magneto-resistive (AMR) sensors integrated with semiconductor circuits and methods of making the same are described. The AMR sensors includes a NiFe alloy layer disposed over a dielectric layer. The NiFe alloy layer is in contact with a conductive via coupled to the semiconductor circuits in a substrate underneath the AMR sensor. A barrier layer is formed on the dielectric layer to prevent Ni or Fe atoms from diffusing through the dielectric layer toward the semiconductor circuits. Further, a sacrificial layer is used to facilitate forming a planarized surface with ends of the conductive vias exposed without compromising the barrier layer.