Barrier layer for metal insulator metal capacitors

A structure, comprising:

• a planar capacitor structure comprising:
• a first electrode bilayer comprising a first metal nitride layer and a second metal nitride layer, each comprising a different nitrogen concentration, wherein the nitrogen concentration in the second metal nitride layer is greater than the nitrogen concentration in the first metal nitride layer;
• and
• a second electrode bilayer comprising a third metal nitride layer and a fourth metal nitride layer, each comprising a different nitrogen concentration, the second electrode bilayer having a smaller surface area than that of the first electrode bilayer, wherein the nitrogen concentration in the third metal nitride layer is greater than the nitrogen concentration in the fourth metal nitride layer;
• and
• a dielectric layer interposed between the second metal nitride layer of the first electrode bilayer and the third metal nitride layer of the second electrode bilayer, wherein the dielectric layer has a surface area substantially equal to that of the first electrode bilayer;
• an interconnect layer above the planar capacitor structure and directly coupled to the second electrode bilayer,
• wherein a bottom surface of the interconnect layer is coplanar with a top surface of the fourth metal nitride layer;
• an interconnect layer below the planar capacitor structure and directly coupled to the first electrode bilayer;
• and
• an encapsulation layer in direct contact with sidewall surfaces of the first and second electrode bilayers.

A structure, comprising:

• a substrate;
• a metallization layer on the substrate;
• a parallel plate capacitor overlying and in contact with the metallization layer, the parallel plate capacitor comprising:
• a pair of electrodes, each electrode comprising a pair of metal nitride layers, an upper electrode of the pair of electrodes having a smaller surface area than that of a lower electrode of the pair of electrodes, wherein each electrode comprises an inner metal nitride barrier layer and an outer metal-rich metal nitride layer;
• a dielectric layer disposed between, and in contact with, the inner metal nitride barrier layers, wherein the dielectric layer has a surface area substantially equal to the surface area of that of the lower electrode of the pair of electrodes, wherein the inner metal nitride barrier layers comprise a higher nitrogen content than the outer metal-rich metal nitride layers;
• a conductive structure, within the metallization layer, disposed below the parallel plate capacitor and directly coupled to one of the pair of electrodes;
• an encapsulation layer in direct contact with sidewall surfaces of the pair of electrodes;
• and
• an upper conductive structure, wherein a bottom surface of the upper conductive structure is coplanar with a top surface of the outer metal-rich metal nitride layer.