US 2014/0197504 A1 · Mg Discontinuous Insertion Layer for Improving MTJ Shunt

Abstract

A MTJ is disclosed with a discontinuous Mg or Mg alloy layer having a thickness from 1 to 3 Angstroms between a free layer and a capping layer in a bottom spin valve configuration. It is believed the discontinuous Mg layer serves to block conductive material in the capping layer from diffusing through the free layer and into the tunnel barrier layer thereby preventing the formation of conductive channels that function as electrical shunts within the insulation matrix of the tunnel barrier. As a result, the “low tail” percentage in a plot of magnetoresistive ratio vs Rp is minimized which means the number of high performance MTJ elements in a MTJ array is significantly increased, especially when a high temperature anneal is included in the MTJ fabrication process. The discontinuous layer is formed by a low power physical vapor deposition process.

Claims27

Dependent claims

A magnetic tunnel junction (MTJ), comprising:

(a) a free layer having perpendicular magnetic anisotropy (PMA) that contacts a top surface of a tunnel barrier layer;
(b) a capping layer as the uppermost layer in the MTJ;
and
(c) a discontinuous Mg or MgM alloy insertion layer formed between the free layer and the capping layer where M is one of Ta, Ti, V, Mo, Zr, Hf, Pt Pd, W, Nb, Rh, Ru, Cu, Cr, or Ir, and M has a content less than about 5 atomic % in the MgM alloy.

1 more element

Dependencies are inferred from the claim text.

Mg Discontinuous Insertion Layer for Improving MTJ Shunt

Life of this patent

Mg Discontinuous Insertion Layer for Improving MTJ Shunt

Life of this patent

Abstract

Claims27