A three-dimensional (3D) capacitor includes a semiconductor substrate; a fin structure including one or more fins formed on the semiconductor substrate; an insulator material formed between each of the one or more fins; a dielectric layer formed on a first portion of the fin structure; a first electrode formed on the dielectric layer; spacers formed on sidewalls of the first electrode; and a second electrode formed on a second portion of the fin structure. The first and second portions are different. The second electrode includes a surface that is in direct contact with a surface of the spacers.