US Patent 9190260 Topological method to build self-aligned MTJ without a mask

A method of forming a self-aligned MTJ without using a photolithography mask and the resulting device are provided. Embodiments include forming a first electrode over a metal layer, the metal layer recessed in a low-k dielectric layer; forming a MTJ layer over the first electrode; forming a second electrode over the MTJ layer; removing portions of the second electrode, the MTJ layer, and the first electrode down to the low-k dielectric layer; forming a silicon nitride-based layer over the second electrode and the low-k dielectric layer; and planarizing the silicon nitride-based layer down to the second electrode.