US 2009/0213503 A1 · MAGNETIC TUNNEL JUNCTION DEVICE

Abstract

A magnetic tunnel junction (MTJ) (10) employing a dielectric tunneling barrier (16), useful in magnetoresistive random access memories (MRAMs) and other devices, has a synthetic antiferromagnet (SAF) structure (14, 16), comprising two ferromagnetic (FM) layers (26, 41; 51, 58; 61, 68) separated by a coupling layer (38, 56, 66). Improved magnetoresistance (MR) ratio is obtained by providing a further layer (44, 46, 46′, 47, 52, 62), e.g. containing Ta, preferably spaced apart from the coupling layer (38, 56, 66) by a FM layer (41, 30-2, 54). The further layer (44, 46, 46′, 47, 52, 62) may be a Ta dusting layer (44) covered by a FM layer (30-2), or a Ta containing FM alloyed layer (46), or a stack (46′) of interleaved FM and N-FM layers, or other combination (47, 62). Furthering these benefits, another FM layer, e.g., CoFe, NiFe, (30, 30-1, 51, 61) is desirably provided between the further layer (44, 46, 46′, 47, 52, 62) and the tunneling barrier (16). Ta, Zr, Hf, Ti, Mg, Nb, V, Zn, Cr, NiFeX, CoFeX and CoFeBX (X═Ta, Zr, Hf, Ti, Mg, Nb, V, Zn, Cr) are useful for the further layer (44, 46, 46′, 47, 52, 62).

Claims23

Dependent claims

A magnetic tunnel junction device, comprising:

a synthetic antiferromagnet (SAF) structure having at least first and second ferromagnetic (FM) layers separated by a coupling layer, wherein the first FM layer has first and second portions;
a further layer containing Ta, Zr, Hf, Ti, Mg, Nb, V, Zn, Cr or a combination thereof, spaced apart from the coupling layer by at least the first portion of the first FM layer;
and
a dielectric tunnel barrier proximate the second portion of the first FM layer.

1 more element

Dependencies are inferred from the claim text.

Magnetic tunnel junction device

Life of this patent

Magnetic tunnel junction device

Life of this patent

Abstract

Claims23