Bottom electrode structure in memory device
In some embodiments, the present disclosure relates to a method of forming an integrated chip. The method includes forming a reactivity reducing coating over one or more lower interconnect layers disposed over a substrate. A bottom electrode layer is formed on and in contact with the reactivity reducing coating. The bottom electrode layer has a first electronegativity that is less than or equal to a second electronegativity of the reactivity reducing coating. A data storage element is formed over the bottom electrode layer and a top electrode layer is formed over the data storage element. The top electrode layer, the data storage element, the reactivity reducing coating, and the bottom electrode layer are patterned to define a memory device.
1 . A method of forming an integrated chip, the method comprising:
forming a reactivity reducing coating over one or more lower interconnect layers disposed over a substrate;
forming a plurality of additional conductive materials onto the one or more lower interconnect layers prior to forming the reactivity reducing coating, wherein the plurality of additional conductive materials comprise a first additional conductive material and a second additional conductive material formed onto a topmost surface of the first additional conductive material, the second additional conductive material being a different material than the first additional conductive material;
forming a bottom electrode layer on and in contact with the reactivity reducing coating, wherein the bottom electrode layer has a first electronegativity that is less than or equal to a second electronegativity of the reactivity reducing coating as measured by numerical values according to Pauling's scale;
forming a data storage element over the bottom electrode layer;
forming a top electrode layer over the data storage element; and
patterning the top electrode layer, the data storage element, the reactivity reducing coating, and the bottom electrode layer to define a memory device.
2 . The method of claim 1 , wherein a lower surface of the bottom electrode layer physically contacts an upper surface of the reactivity reducing coating, the lower surface of the bottom electrode layer facing the substrate.
3 . The method of claim 1 , wherein the reactivity reducing coating is disposed directly between the bottom electrode layer and the substrate after forming the bottom electrode layer.
4 . The method of claim 1 , further comprising:
forming a capping layer onto an upper surface of the data storage element that faces away from the substrate, wherein the capping layer is separated from the reactivity reducing coating by both the data storage element and the bottom electrode layer.
5 . The method of claim 1 , wherein the reactivity reducing coating is formed prior to forming the bottom electrode layer.
6 . The method of claim 1 , wherein the reactivity reducing coating is a metal or a doped polysilicon.
7 . The method of claim 1 , wherein the data storage element is configured to enable formation of a conductive filament of oxygen vacancies within and across the data storage element upon application of a bias voltage across the data storage element.
8 . The method of claim 1 , wherein the bottom electrode layer continuously extends between a bottom surface of the bottom electrode layer that physically contacts the reactivity reducing coating and a top surface of the bottom electrode layer that physically contacts the data storage element.
9 . A method of forming an integrated chip, the method comprising:
forming an opening to extend through an insulating structure and expose an interconnect within a dielectric structure over a substrate;
forming a reactivity reducing coating directly between sidewalls of the insulating structure forming the opening;
forming a bottom electrode layer on the reactivity reducing coating and over an upper surface of the insulating structure, wherein the bottom electrode layer has a first electronegativity that is less than or equal to a second electronegativity of the reactivity reducing coating as measured by numerical values according to Pauling's scale and wherein a difference between the first electronegativity and the second electronegativity is greater than 0.2;
forming a data storage element over the bottom electrode layer;
forming a top electrode layer over the data storage element; and
forming a memory device by removing parts of the top electrode layer, the data storage element, the reactivity reducing coating, and the bottom electrode layer.
10 . The method of claim 9 ,
wherein the reactivity reducing coating is a metal or a doped polysilicon; and
wherein the data storage element is a metal-oxide.
11 . The method of claim 9 , wherein the second electronegativity is greater than 1.5.
12 . The method of claim 9 , wherein the data storage element comprises a material that is configured to enable formation of a conductive filament of oxygen vacancies by movement of oxygen atoms from the data storage element to the top electrode layer during operation.
13 . The method of claim 9 , further comprising:
forming a capping layer onto an upper surface of the data storage element that faces away from the reactivity reducing coating prior to forming the top electrode layer, wherein the capping layer is a metal or a metal-oxide.
14 . The method of claim 9 , wherein the reactivity reducing coating has a curved outer sidewall after removing the parts of the reactivity reducing coating to form the memory device.
15 . A method of forming an integrated chip, the method comprising:
forming a diffusion barrier over an upper surface of an interconnect within an inter-level dielectric (ILD), the upper surface facing away from a substrate;
forming a reactivity reducing coating onto an upper surface of the diffusion barrier;
forming a bottom electrode layer on and in contact with an upper surface of the reactivity reducing coating that faces away from the reactivity reducing coating, wherein the bottom electrode layer has a first electronegativity that is less than or equal to a second electronegativity of the reactivity reducing coating as measured by numerical values according to Pauling's scale;
forming a data storage element on and in contact with an upper surface of the bottom electrode layer that faces away from the reactivity reducing coating;
forming a top electrode layer over the data storage element, the top electrode layer being separated from the bottom electrode layer by the data storage element; and
performing one or more etching processes to remove parts of the top electrode layer, the data storage element, the reactivity reducing coating, and the bottom electrode layer.
16 . The method of claim 15 , wherein the reactivity reducing coating is formed to have a thickness that varies over a width of the reactivity reducing coating.
17 . The method of claim 15 , wherein a bottom surface of the reactivity reducing coating has a first width and a top surface of the reactivity reducing coating has a second width that is different than the first width.
18 . The method of claim 15 , wherein the first electronegativity has a first value and the second electronegativity has a larger second value.
19 . The method of claim 15 , wherein the reactivity reducing coating continuously extends between a bottommost surface contacting the diffusion barrier and a topmost surface contacting the bottom electrode layer.
20 . The method of claim 15 , wherein the diffusion barrier laterally separates the reactivity reducing coating from a dielectric material.