US 2006/0051881 A1 · System and method for processing a wafer including stop-on-aluminum processing

Abstract

Magnetic tunnel junction (MTJ) devices can be fabricated by a stop-on-alumina process whereby the tunnel junction layer serves as the stop layer during plasma overetching of the upper magnetic layer. The resulting side walls of the MTJ device are non-vertical in the vicinity of the tunnel junction layer which serves to electrically isolate the upper magnetic layer from the lower magnetic layer. The gas employed during plasma overetching excludes halogen containing species which results in highly selective etching of the magnetic layer vis-à-vis the alumina tunnel barrier layer. The introduction of oxygen in the gas may enhance the reproducibility of the overetch process. Finally, plasma treatment with He and H2 followed by rinsing and baking subsequent to removal of the photoresist mask during the fabrication process enhances yield.

Claims100

Dependent claims

A process of fabricating a magnetic tunnel junction device that comprises the steps of:

(a) forming a first magnetic member;
(b) forming a second magnetic member;
(c) forming an insulating tunnel barrier layer that comprises a dielectric material located between the first magnetic member and the second magnetic member;
(d) forming a contact layer on an upper surface of the second magnetic member;
(e) forming a patterned mask over the contact layer;
(f) selectively removing portions of the contact layer;
(g) removing the patterned mask;
and
(h) selectively removing portions of the second magnetic member and the insulating tunnel barrier layer such that the second magnetic member is electrically isolated from the first magnetic member.

6 more elements

A process of fabricating a magnetic tunnel junction device that comprises the steps of:

(a) forming a first magnetic member that is a fixed ferromagnetic layer having a magnetic moment that is fixed in a preferred direction in the presence of an applied magnetic field in a specified range;
(b) forming a second magnetic member that is free ferromagnetic layer whose magnetic moment is free to rotate in the presence of an applied magnetic field in the specified range;
(c) forming an insulating tunnel barrier layer that comprises a dielectric material located between the first magnetic member and the second magnetic member;
(c) forming an insulating tunnel barrier layer that comprises a dielectric material located between the first magnetic member and the second magnetic member;
(d) forming a contact layer on an upper surface of the second magnetic member;
(e) forming a patterned mask over the contact layer;
(f) selectively removing portions of the contact layer;
(g) removing the patterned mask;
and
(h) selectively removing portions of the second magnetic member and the insulating tunnel layer such that at least one side portion of the second magnetic member and of the insulating tunnel barrier layer define a non-vertical profile which protrudes outwardly from the at least one side portion.

7 more elements

A process of fabricating a magnetic tunnel junction device that comprises the steps of:

(a) forming a lower (or first) magnetic member that is a fixed ferromagnetic layer having a magnetic moment that is fixed in a preferred direction in the presence of an applied magnetic field in a specified range;
(b) forming an upper (or second) magnetic member that is free ferromagnetic layer whose magnetic moment is free to rotate in the presence of an applied magnetic field in the specified range;
(c) forming an insulating tunnel barrier layer that comprises a dielectric material located between the first magnetic member and the second magnetic member;
(c) forming an insulating tunnel barrier layer that comprises a dielectric material located between the lower magnetic member and the upper magnetic member;
(d) forming a contact layer on an upper surface of the upper magnetic member;
(e) forming a patterned mask over the contact layer to create a multilayer structure;
(f) selectively removing portions of the contact layer that are exposed by the patterned mask;
(g) removing the patterned mask subsequent to step (f) to yield a multiplayer device wherein the contact layer has a substantially vertical side profile and the contact layer partially covers the upper magnetic member and wherein the upper magnetic member covers the insulating tunnel barrier layer;
and
(h) selectively removing side portions of the upper magnetic member that are distal from the multilayer device thereby causing the outer perimeter of the upper magnetic member to recede toward the multilayer device and thereby exposing an upper of the insulating tunnel layer so that said exposed upper layer electrically separates the upper magnetic member that has an outer perimeter on the upper surface of the insulating from the lower magnetic member that is underneath the insulating tunnel layer.

7 more elements

Dependencies are inferred from the claim text.

System and method for processing a wafer including stop-on-aluminum processing

Life of this patent

System and method for processing a wafer including stop-on-aluminum processing

Life of this patent

Abstract

Claims100