Patent ID: 6960480

Claim:
A method of forming a magnetic tunneling junction (MTJ) MRAM device with an ultra-thin tunneling barrier layer of high smoothness and breakdown voltage comprising: providing a substrate having a substantially planar upper surface; forming a first NiCr seed layer on said substrate; forming a non-magnetic metal layer on said seed layer; forming a Ta overlayer on said metal layer and sputter-etching said overlayer; forming a second NiCr seed layer on said sputter-etched Ta overlayer; forming an AFM pinning layer on said seed layer; forming a pinned layer on said pinning layer; forming a layer of Al on said pinned layer; and oxidizing said Al layer in a plasma oxidation chamber, by a process of radical oxidation, to form a tunneling barrier layer on said pinned layer, said tunneling barrier layer being ultra-thin, smooth and having a high breakdown voltage as a result of the NiCr seed layer formed on the sputter-etched Ta overlayer; and forming a free layer on said tunneling barrier layer; forming an upper capping layer on said free layer.