Magnetoresistive effect element, magneto-resistive effect head, method for manufacturing the same and magnetic recording apparatus using the same

A magnetoresistive effect element comprising:

• a ferromagnetic tunnel junction film which comprises a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer, a pinning layer immediately adjacent said pinned layer and a protective layer immediately adjacent said pinning layer;
• and
• an insulating layer,
• wherein said ferromagnetic tunnel junction film comprises a pattern of a metallic material sandwiched between one of an oxide and a nitride of said metallic material constituting said protective layer, and
• wherein said pattern of a metallic material is sandwiched between said insulating layer.

A magnetoresistive effect element comprising:

• a lower electrode layer;
• a longitudinal biasing layer formed on said lower electrode layer;
• a ferromagnetic tunnel junction film which comprises a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer and a pinning layer immediately adjacent said pinned layer, at least a part of said free layer being disposed above said longitudinal biasing layer and adjoining said longitudinal biasing layer directly;
• an insulating layer formed at least on a part of said free layer and said longitudinal biasing layer;
• and
• an upper electrode layer formed above said pinning layer and adjoining, at least at a part thereof, said pinning layer directly or with a protective layer interposed therebetween;
• wherein one of an oxide and a nitride of a metallic material constituting said ferromagnetic tunnel junction film is present only at an end portion of a pattern of said ferromagnetic tunnel junction film.

A magnetoresistive effect element comprising:

• a lower electrode layer;
• a longitudinal biasing layer formed on said lower electrode layer;
• a ferromagnetic tunnel junction film which comprises a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer and a pinning layer immediately adjacent said pinned layer, at least a part of said free layer being disposed below said longitudinal biasing layer and adjoining said longitudinal biasing layer with an underlayer interposed therebetween;
• an insulating layer formed on at least a part of said free layer and said longitudinal biasing layer;
• and
• an upper electrode layer formed on said pinning layer and adjoining, at least at a portion thereof, said pinning layer directly or with a protective layer interposed therebetween;
• wherein one of an oxide and a nitride of a metallic material constituting said ferromagnetic tunnel junction film is present only at an end portion of a pattern of said ferromagnetic tunnel junction film.

A magnetoresistive effect element comprising:

• a lower electrode layer;
• a ferromagnetic tunnel junction film which comprises a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer and a pinning layer immediately adjacent said pinned layer, said film being formed on said lower electrode layer, said free layer having a width equal to or less than that of said lower electrode layer when viewed from an air-bearing surface of said element;
• a longitudinal biasing film comprising a film formed by laminating an insulating layer, at least a portion of which adjoins said free layer, and a longitudinal biasing layer formed on said insulating layer, or an insulating material;
• and
• an upper electrode layer disposed above said free layer and adjoining, at least at a portion thereof, said free layer directly or with a protective layer interposed therebetween;
• wherein one of an oxide and a nitride of a metallic material constituting said ferromagnetic tunnel junction film is present only at an end portion of a pattern of said ferromagnetic tunnel junction film.

A magnetoresistive effect element comprising:

• a lower electrode layer;
• a ferromagnetic tunnel junction film which comprises a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer and a pinning layer immediately adjacent said pinned layer, said film being formed on said lower electrode layer, said free layer having a width equal to or less than that of said lower electrode layer when viewed from an air-bearing surface of said element;
• an insulating layer adjoining at a part thereof said free layer;
• a longitudinal biasing layer disposed above said free layer and adjoining, at least at a part thereof, said free layer directly or with an interface control layer interposed therebetween;
• and
• an upper electrode layer disposed above said longitudinal biasing layer and adjoining, at least at a portion thereof, said longitudinal biasing layer;
• wherein one of an oxide and a nitride of a metallic material constituting said ferromagnetic tunnel junction film is present at only an end portion of a pattern of said ferromagnetic tunnel junction film.

A method for manufacturing a magnetoresistive effect element which utilizes as its magnetoresistive effect element a ferromagnetic tunnel junction film comprising the steps of:

• forming a basic structure of said ferromagnetic tunnel junction film, an arrangement of a free layer, a barrier layer immediately adjacent said free layer, a pinned layer immediately adjacent said barrier layer and a pinning layer immediately adjacent said pinned layer;
• when said ferromagnetic tunnel junction film is patterned, stopping patterning said film in the middle of the layers constituting said ferromagnetic tunnel junction film;
• and
• oxidizing or nitriding at least a surface of that region of said ferromagnetic tunnel function film at which said patterning has been stopped in the middle of the layers.