Sidewall spacer structure to increase switching performance of ferroelectric memory device
View Patent ↗Various embodiments of the present disclosure are directed towards an integrated chip including a switching layer over a semiconductor substrate. The switching layer comprises a first metal oxide. An upper conductive structure overlies the switching layer. The switching layer is spaced between opposing sidewalls of the upper conductive structure. A first dielectric layer is disposed along opposing sidewalls of the switching layer. The first dielectric layer comprises a second metal oxide different from the first metal oxide. A top surface of the switching layer and a top surface of the first dielectric layer directly underlie a bottom surface of the upper conductive structure.
1 . An integrated chip, comprising:
a switching layer overlying a semiconductor substrate, wherein the switching layer comprises a first metal oxide;
an upper conductive structure overlying the switching layer, wherein the switching layer is spaced between opposing sidewalls of the upper conductive structure;
a first dielectric layer disposed along and directly contacting first opposing sidewalls of the switching layer, wherein the first dielectric layer comprises a second metal oxide different from the first metal oxide, wherein a top surface of the switching layer and a top surface of the first dielectric layer are aligned and directly underlie a single planar bottommost surface of the upper conductive structure, and wherein a dielectric constant of the switching layer is greater than a dielectric constant of the first dielectric layer; and
a dielectric structure overlying the upper conductive structure and contacting the first dielectric layer, wherein a dielectric constant of the dielectric structure is less than the dielectric constant of the first dielectric layer.
2 . The integrated chip of claim 1 , wherein the first dielectric layer comprises a switching enhancement element disposed along the first opposing sidewalls of the switching layer, wherein the switching enhancement element is laterally offset from a middle region of the switching layer by a non-zero distance.
3 . The integrated chip of claim 1 , wherein the switching layer comprises an outer segment directly under a bottom surface of the first dielectric layer.
4 . The integrated chip of claim 1 , wherein a ratio of a width of the switching layer and a lateral thickness of the first dielectric layer along the first opposing sidewalls of the switching layer is within a range of about 5:1 to 30:1.
5 . The integrated chip of claim 1 , wherein a width of the switching layer is less than a width of the upper conductive structure, and wherein a height of the switching layer is greater than a height of the upper conductive structure.
6 . The integrated chip of claim 1 , wherein the first metal oxide is a ferroelectric material.
7 . The integrated chip of claim 1 , further comprising:
a second dielectric layer disposed between the switching layer and the semiconductor substrate, wherein outer sidewalls of the second dielectric layer are aligned with outer sidewalls of the first dielectric layer.
8 . The integrated chip of claim 1 , wherein the switching layer comprises second opposing sidewalls, wherein the first opposing sidewalls are spaced between the second opposing sidewalls, and wherein the second opposing sidewalls are aligned with outer opposing sidewalls of the first dielectric layer.
9 . The integrated chip of claim 1 , wherein the dielectric structure contacts the switching layer.
10 . An integrated chip, comprising:
a first conductive structure overlying a semiconductor substrate;
a second conductive structure overlying the first conductive structure; and
a switching structure disposed between the first conductive structure and the second conductive structure, wherein the switching structure comprises a switching layer and a first dielectric layer laterally enclosing the switching layer, wherein a sidewall of the switching structure is aligned with a sidewall of the second conductive structure, wherein the switching layer comprises a lateral surface vertically above a bottom surface of the switching layer, wherein a bottom surface of the first dielectric layer contacts the lateral surface.
11 . The integrated chip of claim 10 , wherein the sidewall of the switching structure is defined by an outer sidewall of the first dielectric layer.
12 . The integrated chip of claim 10 , further comprising:
a gate dielectric layer disposed between the first conductive structure and the semiconductor substrate; and
a pair of source/drain regions disposed within the semiconductor substrate on opposing sides of the first conductive structure.
13 . The integrated chip of claim 10 , wherein the switching layer comprises a dielectric material different from that of the first dielectric layer.
14 . The integrated chip of claim 13 , wherein the switching layer and the first dielectric layer physically contact a bottom surface of the second conductive structure.
15 . The integrated chip of claim 10 , wherein a width of the switching layer is within a range of about 20 to 150 nanometers, wherein a lateral thickness of the first dielectric layer along the switching layer is within a range of about 0.2 to 100 angstroms.
16 . An integrated chip, comprising:
a switching layer overlying a semiconductor substrate;
an upper conductive structure over the switching layer; and
a sidewall spacer layer arranged directly on opposing sidewalls of the switching layer, wherein a bottommost surface of the sidewall spacer layer is vertically offset from a bottom surface of the switching layer in a direction away from the semiconductor substrate.
17 . The integrated chip of claim 16 , wherein the bottommost surface of the sidewall spacer layer contacts a lateral surface of the switching layer.
18 . The integrated chip of claim 16 , wherein a top surface of the sidewall spacer layer contacts a bottom surface of the upper conductive structure, and wherein outer sidewalls of the sidewall spacer layer are aligned with outer sidewalls of the upper conductive structure.
19 . The integrated chip of claim 16 , wherein the switching layer comprises a ferroelectric material, and wherein the sidewall spacer layer physically contacts the opposing sidewalls of the switching layer.
20 . The integrated chip of claim 16 , further comprising:
a lower conductive structure on the bottom surface of the switching layer; and
a conductive interconnect structure on the upper conductive structure.