Abstract: A method for forming a storage node electrode of a semiconductor device, includes the steps of: forming a contact plug in an interlayer insulation film on a semiconductor substrate; sequentially stacking etch stop films, a sacrificial insulation film, a polysilicon hard mask and a reflection preventative film on the surface of the interlayer insulation film; forming an opening by etching the hard mask, the sacrificial insulation film and the etch stop films to remove the reflection preventative film to obtain a storage node electrode region; forming a storage node electrode by depositing a conductive material over the resultant structure; forming a filling film for filling up the opening; etching the filling film, the storage node electrode and the hard mask so that the hard mask has a predetermined thickness; and etching the resultant structure with a chemical mechanical polishing process so that the residual hard mask can be completely removed.