HIGH ANNEALING TEMPERATURE PERPENDICULAR MAGNETIC ANISOTROPY STRUCTURE FOR MAGNETIC RANDOM ACCESS MEMORY

摘要

A perpendicular synthetic antiferromagnetic (pSAF) structure and method of making such a structure is disclosed. The pSAF structure comprises a first high perpendicular Magnetic Anisotropy (PMA) multilayer and a second high PMA layer separated by a thin Ruthenium layer. Each PMA layer is comprised of a first cobalt layer and a second cobalt layer separated by a nickel/cobalt multilayer. After each of the first and second PMA layers and the Ruthenium exchange coupling layer are deposited, the resulting structure goes through a high temperature annealing step, which results in each of the first and second PMA layers having a perpendicular magnetic anisotropy.

主权项

1. A magnetic device, comprising
a PMA seed multilayer comprised of a first seed layer and a nickel seed layer, the Ni seed layer being disposed over the first seed layer; a first magnetic perpendicular magnetic anisotropy (PMA) multilayer disposed over the PMA seed multilayer, the first magnetic PMA multilayer comprising a first cobalt (Co) layer and a second Co layer, where the first Co layer and the second Co layer are separated by a first nickel/cobalt (Ni/Co) multilayer, wherein the first magnetic PMA multilayer has been annealed at a high temperature and has a magnetic direction perpendicular to its plane; a thin Ruthenium (Ru) antiferromagnetic interlayer exchange coupling layer disposed over the first magnetic PMA multilayer; a second magnetic PMA multilayer disposed over the thin Ru antiferromagnetic interlayer exchange coupling layer, the second magnetic PMA multilayer comprising a third Co layer and a fourth Co layer, where the third Co layer and the fourth Co layer are separated by a second nickel/cobalt (Ni/Co) multilayer, wherein the second magnetic PMA multilayer has been annealed at the high temperature and has a magnetic direction perpendicular to its plane; wherein the first magnetic PMA multilayer, the thin Ru interlayer exchange coupling layer and the second magnetic PMA multilayer form a perpendicular synthetic antiferromagnet.