Methods of manufacturing a capacitor and a semiconductor device

In methods of manufacturing a capacitor and a semiconductor device, a mold layer is formed on a substrate having a contact plug. The mold layer includes an opening exposing the contact plug. A conductive layer is formed on the contact plug, an inner sidewall of the opening and the mold layer. A photoresist pattern is formed to substantially fill the opening. A cylindrical lower electrode is formed by partially removing the conductive layer. The mold layer is selectively removed while the photoresist pattern prevents damage to the lower electrode, the contact plug and the substrate. The photoresist pattern is removed, and then a dielectric layer and an upper electrode are sequentially formed on the lower electrode. Damage to the lower electrode and the contact plug are effectively prevented due to the presence of the photoresist pattern during selective removal of the mold layer.