MgO insertion into free layer for magnetic memory applications

A method of forming a magnetic element exhibiting interfacial perpendicular anisotropy at a first interface between a free layer and a first oxide layer, and at a plurality of interfaces where the free layer contacts a plurality of metal oxide clusters formed within the free layer, comprising:

• (a) providing the first oxide layer or a first non-magnetic metal or alloy (NM1) layer on a substrate;
• (b) depositing the free layer (FL) with a plurality of metal clusters therein on the first oxide layer or on the NM1 layer;
• (c) depositing a second oxide layer or a second non-magnetic metal or alloy (NM2) layer on a top surface of the free layer that faces away from the first oxide layer or the NM1 layer;
• and
• (d) performing an annealing step such that during one or more of steps (b), (c), and (d), the plurality of metal clusters scavenge oxygen from one or more layers in the magnetic element, and react with the scavenged oxygen to form a plurality of metal oxide clusters that interface with portions of the free layer thereby enhancing perpendicular magnetic anisotropy (PMA) therein.

A method of forming a magnetic element exhibiting interfacial perpendicular anisotropy at a first interface between a free layer and a first oxide layer, and at a plurality of interfaces where the free layer contacts a plurality of metal oxide regions in a metal layer having a non-stoichiometric oxidation state that is formed within the free layer, comprising:

• (a) providing the first oxide layer or a first non-magnetic (NM1) layer on a substrate;
• (b) depositing a first free layer (FL1) on the first oxide layer or the NM1 layer;
• (c) depositing a metal (M) layer or MQ alloy layer on the first free layer where M is a first metal and Q is a second metal that is unequal to M;
• (d) depositing a second free layer (FL2) on the M layer or MQ alloy layer to give a composite free layer with a FL1/M/FL2 or FL1/MQ/FL2 configuration;
• (e) depositing a second oxide layer or a second non-magnetic metal or alloy (NM2) layer on a surface of second free layer that faces away from the first oxide layer;
• and
• (f) performing an annealing step such that during one or more of steps (d), (e), and (f), a plurality of metal atoms in the M layer or MQ alloy layer scavenge oxygen from one or more layers in the magnetic element, and react with the scavenged oxygen to form a plurality of metal oxide regions on the M or MQ alloy layer that interface with portions of the FL1 and the FL2 thereby enhancing perpendicular magnetic anisotropy (PMA) in the composite free layer.

A method of forming a magnetic element exhibiting interfacial perpendicular anisotropy at a first interface between a composite free layer and a first oxide layer or a first non-magnetic metal or alloy (NM1) layer, at a second interface between the composite free layer and a second oxide layer or a second non-magnetic metal or alloy (NM2) layer, and at a plurality of interfaces where the composite free layer contacts a plurality of metal oxide regions in two metal layers each having a non-stoichiometric oxidation state that are formed within the composite free layer, comprising:

• (a) providing the first oxide layer or the NM1 layer on a substrate;
• (b) depositing a first free layer (FL1) on the first oxide layer or the NM1 layer;
• (c) depositing a first metal layer (M) or a first alloy (MQ) layer on FL1 where M is a first metal and Q is a second metal;
• (d) depositing a second free layer (FL2) on the first M layer or first MQ layer;
• (e) depositing a second metal layer (M2) or a second alloy layer (M2Q2) on the FL2;
• (f) depositing a third free layer (FL3) on the M2 layer or M2Q2 layer to give the composite free layer comprising a FL1/M/FL2/M2/FL3, FL1/M/FL2/M2Q2/FL3, FL1/MQ/FL2/M2Q2/FL3, or FL1/MQ/FL2/M2/FL3 stack of layers;
• (g) depositing the second oxide layer or the NM2 layer on a top surface of the composite free layer that faces away from the first oxide or NM1 layer;
• and
• (h) performing an annealing step such that during one or more of steps (f), (g), and (h) a plurality of M and/or Q metal atoms in the M, M2, MQ, and M2Q2 layers scavenge oxygen from one or more layers in the magnetic element, and react with the scavenged oxygen to form a plurality of metal oxide regions on the M or MQ layer that interface with portions of the FL1 and the FL2, and a plurality of metal oxide regions on the M2 or M2Q2 layer that interfaces with portions of the FL2 and the FL3 thereby enhancing perpendicular magnetic anisotropy (PMA) in the composite free layer.