To reduce dent defects formed in interlayer CMP process on a capacitor array after forming an interlayer insulating film on the capacitor array thicker than the height of a capacitor, the interlayer insulating film on the capacitor array is subjected to a step height reduction etching to form an opening with etching depth Hd, while remaining a first region that is a distance Lr in a horizontal direction from a rising point of a projected portion of the interlayer insulating film periphery to the capacitor array onto a part of the capacitor array, wherein an aspect ratio (Hd/Lr) of the Hd to the Lr is equal to or less than 0.6.