Magnetic Element with Perpendicular Magnetic Anisotropy (PMA) and Improved Coercivity Field (Hc)/Switching Current Ratio

A perpendicular magnetic tunnel junction (p-MTJ) structure, comprising:

• (a) a pinned layer (PL);
• (b) a tunnel barrier layer with a first surface that adjoins the PL, and a second surface that contacts a free layer (FL) and forms a first interface with the FL;
• (c) the FL that has a first metal insertion (MIS1) layer formed within one of a first FL sub-layer (FL1) and a second FL sub-layer (FL2), and wherein the FL has perpendicular magnetic anisotropy (PMA) as a result of the first interface, as a result of a second interface with a Hk enhancing layer;
• (d) the Hk enhancing layer having a non-stoichiometric oxidation condition, and that adjoins the FL to form the second interface on a side of the FL that is opposite to the first interface;
• and
• (e) a nitride capping layer (NCL), comprising:
• (1) a nitride layer (NL) that is a metal nitride or metal oxynitride;
• and
• (2) a buffer layer that adjoins the NL and contacts the Hk enhancing layer on a side thereof that is opposite to the second interface, wherein the buffer layer prevents oxygen diffusion from the Hk enhancing layer to the NL, and blocks nitrogen diffusion from the NL to the FL.

A method of forming a perpendicular magnetic tunnel junction (p-MTJ) having a first interface between a free layer (FL) and a first oxide layer that is a tunnel barrier layer, and a second interface between the FL and a Hk enhancing layer that is a second metal oxide layer or a metal oxynitride layer, comprising:

• (a) forming the FL on the tunnel barrier layer with a sputter deposition sequence, comprising;
• (1) depositing a first FL sub-layer on the tunnel barrier layer to form an interface that enhances perpendicular magnetic anisotropy in the FL;
• (2) depositing a first metal insertion (MIS1) layer on the first FL sub-layer;
• and
• (3) depositing a second FL sub-layer on the MIS1 layer;
• (b) forming a Hk enhancing layer that is a metal oxide layer on the FL;
• and
• (c) sequentially depositing a buffer layer and a nitride layer (NL) that is a metal nitride or metal oxynitride on the Hk enhancing layer wherein the buffer layer prevents oxygen diffusion from the Hk enhancing layer to the NL, and blocks nitrogen diffusion from the NL to the FL.