Interconnect structure with capacitor and methods for making

A method for making a capacitor, comprising:

• forming a trench in a dielectric material;
• depositing a first metal on sidewalls and a bottom surface of the trench, and upon a surface of the dielectric material to form a first metal layer;
• depositing a first insulator upon the first metal layer on the sidewalls and the bottom surface of the trench, and upon the surface of the dielectric material to form a first insulator layer;
• depositing a second metal upon the first insulator layer on sidewalls and the bottom surface of the trench, over a second insulator in the trench, and upon the surface of the dielectric material to form a second metal layer;
• planarizing to removing portions of the second metal layer and the first insulator layer upon the surface of the dielectric material;
• applying a primary insulator upon the surface of the dielectric material to isolate the second metal in the trench;
• forming a third metal layer upon the first insulator layer upon the surface of the dielectric material;
• and
• patterning to form a first horizontal plate from the first metal layer, a second horizontal plate from the first insulator layer, and a third horizontal plate from the third metal layer to obtain the capacitor.