US 6,544,801 B1Granted

Method of fabricating thermally stable MTJ cell and apparatus

AssigneeMotorola, Inc.

InventorsJon Slaughter, Saied Tehrani, Eugene Chen, Mark Durlam, Mark DeHerrera, Renu Whig Dave

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Abstract

An MTJ cell including an insulator layer of material between magnetic material layers with the insulator layer of material having a greater attraction for a third material than the magnetic material layers. The third material is introduced to one or both so that when the cell is heated the third material is redistributed from the magnetic material layer to the insulator layer. Upon redistribution the insulator layer becomes an insulator layer material. Also, a first diffusion barrier layer is positioned between a first metal electrode and one of the magnetic material layers and/or a second diffusion barrier layer is positioned between a second metal electrode and the other magnetic material layer to prevent diffusion of the metal in the electrodes into the magnetic material layers.

Claims50

Dependent claims

A method of fabricating an MTJ cell comprising the steps of:

forming a stack of layers of material including a first metal electrode, a first layer of magnetic material in electrical communication with the first metal electrode, an insulator layer of material, a second layer of magnetic material, and a second metal electrode in electrical communication with the second layer of magnetic material;
the step of forming the stack of layers of material including the steps of:
positioning the insulator layer of material on the first layer of magnetic material, the insulator layer of material having a greater attraction for a third material than the first layer of magnetic material and the insulator layer of material forming insulator layer material with the third material;
positioning the second layer of magnetic material on the insulator layer of material, the insulator layer of material having a greater attraction for the third material than the second layer of magnetic material;
and
introducing the third material to one of the first layer of magnetic material and the second layer of magnetic material during the steps of positioning the insulator layer of material on the first layer of magnetic material, and positioning the second layer of magnetic material on the insulator layer of material;
positioning at least one diffusion barrier layer in accordance with at least one of:
between the first metal electrode and the first layer of magnetic material;
and between the second metal electrode and the second layer of magnetic material during the step of forming the stack of layers wherein the diffusion barrier layer includes a metallization layer and wherein the diffusion barrier layer is formed by exposing the metallization layer to ions or radicals;
and
heating the stack of layers to redistribute the third material from the one of the first layer of magnetic material and the second layer of magnetic material to the insulator layer of material.

8 more elements

A method of fabricating an MTJ cell comprising the steps of:

providing a first metal electrode;
positioning a first diffusion barrier layer on the first metal electrode wherein the first diffusion barrier layer is formed by exposing a first metallization layer to ions or radicals of nitrogen;
positioning a first layer of magnetic material in electrical communication with the first metal electrode so that the first diffusion barrier layer is positioned between the first metal electrode and the first layer of magnetic material;
positioning an insulator layer of material on the first layer of magnetic material;
positioning a second layer of magnetic material on the insulator layer of material;
and
positioning a second diffusion barrier layer on the second layer of magnetic material and in electrical communication with a second metal electrode so that the second diffusion barrier layer is positioned between the second metal electrode and the second layer of magnetic material wherein the second diffusion barrier layer is formed by exposing a second metallization layer to ions or radicals of nitrogen.

4 more elements

A method of fabricating an MTJ cell comprising the steps of:

providing a first layer of magnetic material;
positioning an insulator layer of material on the first layer, the insulator layer of material having a greater tendency to attract a third material than the first layer of magnetic material, and the insulator layer of material forming insulator layer material with the third material;
positioning a second layer of magnetic material on the insulator layer of material, the insulator layer or material having a greater Lendency to attract the third material than the second layer of magnetic material;
during the steps of providing the first layer, positioning the insulator layer of material on the first layer, and positioning the second layer of magnetic material on the insulator layer of material, introducing the third material to one of the first layer of magnetic material and the second layer of magnetic material;
positioning a diffusion barrier layer on at least one of the first and second layer of magnetic material wherein the diffusion barrier layer is formed by exposing a metallization layer to ions or radicals and wherein the metallization layer includes at least one of Ta and Al;
and
heating the first layer of magnetic material, the insulator layer of material, and the second layer of magnetic material to redistribute the third material from the one of the first layer of magnetic material and the second layer of magnetic material to the insulator layer of material.

4 more elements

Dependencies are inferred from the claim text.