Memory structure with non-ion beam etched MTJ and top electrode
A memory structure including a magnetic tunnel junction (MTJ) structure and a top electrode that are both formed without utilizing ion beam etching is provided. The MTJ structure, which includes a lower magnetic stack, a tunnel barrier layer and an upper magnetic stack, is pyramidal shaped, and end portions of the lower magnetic stack of the MTJ structure are devoid of the tunnel barrier layer and the upper magnetic stack.
1 . A memory structure comprising:
a magnetic tunnel junction (MTJ) structure located on an electrically conductive structure, the MTJ structure comprising a lower magnetic stack and an upper magnetic stack that are spaced apart by a tunnel barrier layer;
a top electrode located on the upper magnetic stack of the MTJ structure, wherein the top electrode contains a seam; and
a sacrificial dielectric material layer protecting an upper portion of a sidewall of the top electrode, wherein the sacrificial dielectric material layer has a residual magnetic stack located on a sidewall thereof.
2 . The memory structure of claim 1 , wherein the top electrode has a constant width throughout an entirety of the top electrode.
3 . The memory structure of claim 1 , wherein the electrically conductive structure is embedded in an interconnect dielectric material layer, and the electrically conductive structure and the interconnect dielectric material layer collectively form an interconnect level.
4 . The memory structure of claim 1 , wherein the MTJ structure is pyramidal in shape.
5 . The memory structure of claim 4 , wherein the lower magnetic stack of the MTJ structure has a first width, the tunnel barrier layer of the MTJ structure has a second width, and the upper magnetic stack of the MTJ structure has a third width, wherein the first width is greater than the second width and the third width, and the second width is greater than, or equal to, the third width.
6 . The memory structure of claim 5 , wherein the top electrode has a fourth width, wherein the fourth width is less than the first width, and the fourth width is equal to, or less than, the second width and the third width.
7 . The memory structure of claim 1 , wherein the MTJ structure is a top pinned MTJ structure, and the lower magnetic stack comprises a magnetic free layer, and the upper magnetic stack comprises a magnetic reference layer.
8 . The memory structure of claim 1 , wherein the MTJ structure is a bottom pinned MTJ structure, and the lower magnetic stack comprises a magnetic reference layer, and the upper magnetic stack comprises a magnetic free layer.
9 . The memory structure of claim 1 , wherein the lower magnetic stack further comprises a bottom electrode, the bottom electrode is located in close proximity to the electrically conductive structure.
10 . The memory structure of claim 1 , wherein the lower magnetic stack has an end portion that is devoid of the tunnel barrier layer and the upper magnetic stack.
11 . The memory structure of claim 1 , wherein the seam is present in a middle portion of the top electrode.
12 . The memory structure of claim 11 , wherein the seam extends outwards from the middle portion to the sidewall of the top electrode.
13 . A memory structure comprising:
a magnetic tunnel junction (MTJ) structure located on an electrically conductive structure, the MTJ structure comprising a lower magnetic stack and an upper magnetic stack that are spaced apart by a tunnel barrier layer;
a top electrode located on the upper magnetic stack of the MTJ structure, wherein the top electrode contains a seam; and
a sacrificial dielectric material layer protecting an upper portion of a sidewall of the top electrode, wherein a gap is present between a bottommost surface of the sacrificial dielectric material layer and a topmost surface of the MTJ structure and the sacrificial dielectric material layer has a residual magnetic stack located on a sidewall thereof.