Abstract: A method of forming a capacitor for DRAM according to the invention is disclosed. The method includes the follow steps: a dielectric layer, an etching stop layer, a first insulating layer, a first conductive layer and a second insulating layer are formed in order on a substrate. A contact hole is formed in the second insulating layer. the first conductive layer, the first insulating layer, the etching stop layer and the dielectric layer. Then, a second conductive layer is formed over the substrate and completely fills the contact hole. The second conductive layer is patterned. Next, a silicon nitride layer is formed adjacently to the patterned second conductive layer. Parts of the second insulating layer and the first conductive layer are removed by using the silicon nitride layer as a mask, thereby exposing parts of the first insulating layer. Afterwards, a third conductive layer is formed over the substrate.