Patent ID: 7105372
Filing Date: 2006-09-12
Classification: B82Y,G11C,H01F,H01L

Abstract:
1. A method for forming an MTJ memory cell having a substantially circular horizontal cross-section, wherein a ferromagnetic free layer in said cell has uniaxial magnetic anisotropy provided by exchange coupling with a top antiferromagnetic layer formed thereon comprising: providing a substrate; forming on said substrate a layered magnetic tunneling junction (MTJ) structure, said formation further comprising: forming on said substrate a seed layer; forming on said seed layer an antiferromagnetic pinning layer; forming on said antiferromagnetic pinning layer a synthetic antiferromagnetic (SyAF) pinned layer; forming on said pinned layer a tunneling barrier layer; forming on said tunneling barrier layer a ferromagnetic free layer; forming on said ferromagnetic free layer said top antiferromagnetic layer; forming on said top antiferromagnetic layer a capping layer; annealing said layered MTJ structure in an external magnetic field, thereby pinning said SyAF layer and exchange coupling said top antiferromagnetic layer to said ferromagnetic free layer to produce, thereby, a uniaxial magnetic anisotropy in said free layer; patterning said layered MTJ structure to create a horizontal cross-sectional shape that is substantially circular.