Co/Ni Multilayers with Improved Out-of-Plane Anisotropy for Magnetic Device Applications

摘要

A MTJ for a spintronic device is disclosed and includes a thin seed layer that enhances perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (Co/Ni)n composition or the like where n is from 2 to 30. The seed layer is preferably NiCr, NiFeCr, Hf, or a composite thereof with a thickness from 10 to 100 Angstroms. Furthermore, a magnetic layer such as CoFeB may be formed between the laminated layer and a tunnel barrier layer to serve as a transitional layer between a (111) laminate and (100) MgO tunnel barrier. There may be a Ta insertion layer between the CoFeB layer and laminated layer to promote (100) crystallization in the CoFeB layer. The laminated layer may be used as a dipole layer in a MTJ. Annealing between 300° C. and 400° C. may be used to further enhance PMA in the laminated layer.

主权项

1. A magnetic tunnel junction (MTJ), comprising:
(a) a reference layer formed on a substrate; (b) a tunnel barrier layer contacting a top surface of the reference layer; (c) a free layer formed on the tunnel barrier layer; (d) a first non-magnetic spacer contacting a top surface of the free layer; and (e) a dipole layer contacting a top surface of the non-magnetic spacer, the dipole layer has a lower underlayer comprising one or more of Hf, NiFeCr, and NiCr, and an upper laminated layer that has intrinsic perpendicular magnetic anisotropy (PMA) and includes two magnetic elements, a magnetic element and alloy, or two alloys represented by (A1/A2)n or (A1/C/A2) where A1 is a first magnetic element or alloy, A2 is a second magnetic element or alloy, C is a second non-magnetic spacer, and n is the number of laminates in the laminated layer.