Magnetic tunnel junction device having an intermediate layer
AssigneeU.S. Philips Corporation
InventorWouter Oepts
Life of this patent
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Abstract
A magnetic tunnel junction device has a multi-layer structure including a pair of electrode layers of a ferromagnetic material and a tunnel barrier layer of an insulating material between the electrode layers. In order to realize a low resistance, the multi-layer structure also includes an intermediate layer provided between the barrier layer and one of the electrode layers and including a conductive material having a work function with a value which is at least 25% lower than the value of the work function of the material of the respective electrode layer.
Claims12
A magnetic tunnel junction device provided with a multi-layer structure comprising
- a pair of electrode layers of a ferromagnetic material;
- a tunnel barrier layer of an insulating material, interposed between the electrode layers;
- and
- an intermediate layer provided between the tunnel barrier layer and one of the electrode layers, which intermediate layer includes a conductive material having a work function with a value which is at least 25% lower than a value of a work function of the material of the one electrode layer.
A magnetic field sensor comprising:
- a transducer element formed by a magnetic tunnel junction device including:
- a pair of electrode layers of a ferromagnetic material;
- a tunnel barrier layer of an insulating material, interposed between the electrode layers;
- and
- an intermediate layer provided between the tunnel barrier layer and one of the electrode layers, which intermediate layer includes a conductive material having a work function with a value which is at least 25% lower than a value of a work function of the material of the one electrode layer;
- the sensor further comprising an output for a magnetic field signal.
The magnetic head comprising:
- a magnetic field sensor having a transducer element formed by a magnetic tunnel junction device including:
- a pair of electrode layers of a ferromagnetic material;
- a tunnel barrier layer of an insulating material, interposed between the electrode layers;
- and
- an intermediate layer provided between the tunnel barrier layer and one of the electrode layers, which intermediate layer includes a conductive material having a work function with a value which is at least 25% lower than a value of a work function of the material of the one electrode layer;
- the magnetic head further comprising a magnetic yoke for cooperation with the magnetic tunnel junction device.
A system for reading information from a magnetic information carrier, the system comprising:
- a magnetic field sensor with a transducer element formed by a magnetic tunnel junction device including:
- a pair of electrode layers of a ferromagnetic material;
- a tunnel barrier layer of an insulating material, interposed between the electrode layers;
- and
- an intermediate layer provided between the tunnel barrier layer and one of the electrode layers, which intermediate layer includes a conductive material having a work function with a value which is at least 25% lower than a value of a work function of the material of the one electrode layer;
- the system further comprising an output for information read from the information carrier.
A magnetic tunnel junction memory cell comprising:
- a magnetic tunnel junction device including:
- a pair of electrode layers of a ferromagnetic material;
- a tunnel barrier layer of an insulating material, interposed between the electrode layers;
- and
- an intermediate layer provided between the tunnel barrier layer and one of the electrode layers, which intermediate layer includes a conductive material having a work function with a value which is at least 25% lower than a value of a work function of the material of the one electrode layer;
- the memory cell further comprising an output for information stored in the memory cell.
Dependencies are inferred from the claim text.