Method of forming self-aligned stacked capacitor

Abstract

A method of forming a self-aligned stacked capacitor on a substrate having a first insulation layer thereon. A bit line contact and a first section node contact are formed in the first insulation layer, and then a bit line structure is formed over the first insulation layer. The bit line structure includes a bit line, a cap layer and spacers. The bit line and the bit line contact are electrically connected. The cap layer is formed above the bit line while the spacers are formed on the sidewalls of the bit line and the cap layer. A second insulation layer, an etching stop layer and a third insulation layer are sequentially formed over the substrate. An opening is formed in the third insulation layer, the etching stop layer and the second insulation layer to expose a portion of the bit line structure and the first section node contact. A conformal first conductive layer is formed over the interior surface of the opening. The first conductive layer forms a second section node contact as well as a crown-shaped lower electrode. Finally, a conformal dielectric layer and a second conductive layer are sequentially formed over the substrate. The second conductive layer forms the upper electrode of the crown-shaped capacitor.