Method for fabricating capacitors in semiconductor integrated circuit

摘要

A capacitor is formed by providing a substrate, which has conductive structures with cap layer formed thereon. A first dielectric layer is formed over the substrate and the conductive structures. The first dielectric layer is patterned to form an opening to expose the substrate between the conductive structures and the sidewalls of the conductive structures. A conductive plug fills the opening. A second dielectric layer is formed over the first dielectric layer and the conductive plug. The second dielectric layer is patterned to form a narrow opening to expose the conductive plug. A conductive bar is formed to fill the narrow opening. The second dielectric layer is removed. A dielectric spacer is formed on the sidewall of the conductive bar. A conductive spacer is formed on the dielectric spacer. The conductive spacer has electric contact with the conductive plug. The dielectric spacer is removed by isotropic etching. Then, a conformal capacitor dielectric layer and an electrode conductive layer are sequentially formed over the substrate.