Patent ID: 7994596

Claim:
An MTJ memory cell having a substantially circular horizontal cross-section, wherein a ferromagnetic free layer in said cell has a magnetic anisotropy provided by magnetic coupling with an antiferromagnetic layer comprising: a substrate; a layered magnetic tunneling junction (MTJ) structure, formed on said substrate, said MTJ structure comprising: a seed layer; a bottom antiferromagnetic layer formed on said seed layer; a synthetic antiferromagnetic (SyAF) pinned layer formed on said bottom antiferromagnetic layer; a tunneling barrier layer formed on said SyAF pinned layer; a ferromagnetic free layer formed on said tunneling barrier layer; a thin top antiferromagnetic layer, of thickness less than 20 angstroms, formed on said ferromagnetic free layer; a capping layer formed on said thin top antiferromagnetic layer; and wherein said thin top antiferromagnetic layer of thickness less than 20 angstroms is magnetically coupled to said ferromagnetic free layer by interfacial exchange coupling across an interface between said thin top antiferromagnetic layer and said ferromagnetic free layer to produce, thereby, a simultaneously optimized coercivity and magnetic anisotropy in said ferromagnetic free layer and wherein said magnetic anisotropy has zero unidirectionality; and wherein said bottom antiferromagnetic layer is exchange coupled to said SyAF pinned layer.