Dielectric isolation for mram array
AssigneeInternational Business Machines Corporation
InventorsOscar van der Straten, Koichi Motoyama, Chih-Chao Yang
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Abstract
A magnetoresistive random access memory (MRAM) includes a pillar structure having a bottom electrode, a magnetic tunnel junction (MTJ) and a top electrode disposed on the MTJ. The MTJ has a reference layer, a free layer and a tunnel barrier disposed between the reference layer and the free layer. The MTJ is disposed on the bottom electrode. The bottom electrode and the top electrode are recessed within a periphery of the MTJ to form a disrupted sidewall profile.
Claims19
A magnetoresistive random access memory (MRAM), comprising:
- a pillar structure having:
- a bottom electrode;
- a magnetic tunnel junction (MTJ) having a reference layer, a free layer and a tunnel barrier disposed between the reference layer and the free layer, the MTJ disposed on the bottom electrode;
- and
- a top electrode disposed on the MTJ;
- wherein the bottom electrode and the top electrode are recessed within a periphery of the MTJ to form a disrupted sidewall profile.
A method for making a magnetoresistive random access memory (MRAM), comprising:
- forming a bottom electrode having a first footprint;
- forming a first sublayer of an interlevel dielectric layer corresponding to a level of the bottom electrode;
- forming a first ferromagnetic layer on the bottom electrode having a second footprint that is larger than the first footprint;
- forming a second sublayer of the interlevel dielectric layer corresponding to a level of the first ferromagnetic layer;
- forming a tunnel barrier on the first ferromagnetic layer within the first footprint;
- forming a dielectric ring in a plane of the tunnel barrier and extending between the first footprint and the second footprint;
- forming a second ferromagnetic layer on the tunnel barrier and the dielectric ring, the second ferromagnetic layer having the second footprint;
- forming a third sublayer of the interlevel dielectric layer corresponding to a level of the second ferromagnetic layer;
- and
- forming a top electrode having the first footprint.
A method for making a magnetoresistive random access memory (MRAM), comprising:
- forming a bottom electrode having a first footprint;
- forming a first sublayer of an interlevel dielectric layer corresponding to a level of the bottom electrode;
- forming a first ferromagnetic layer on the bottom electrode having a second footprint that is larger than the first footprint;
- forming a first portion of a sidewall spacer on sidewalls of the first ferromagnetic layer;
- forming a second sublayer of the interlevel dielectric layer corresponding to a level of the first ferromagnetic layer;
- forming a tunnel barrier on the first ferromagnetic layer within the first footprint;
- forming a dielectric ring in a plane of the tunnel barrier and extending between the first footprint and the second footprint;
- forming a second ferromagnetic layer on the tunnel barrier and the dielectric ring, the second ferromagnetic layer having the second footprint;
- forming a second portion of a sidewall spacer on sidewalls of the second ferromagnetic layer, wherein the first portion of the sidewall spacer and the second portion of the sidewall spacer intersect at the dielectric ring;
- forming a third sublayer of the interlevel dielectric layer corresponding to a level of the second ferromagnetic layer;
- forming a top electrode having the first footprint;
- and
- forming a fourth sublayer of the interlevel dielectric layer corresponding to a level of the top electrode.
Dependencies are inferred from the claim text.