and development of the photoresist then a contact hole that exposes a predetermined surface portion of the impurity region 21 is formed by etching the insulating interlayer 22 while using the photoresist pattern as an etch mask a conductive layer of w is formed by cvd on the insulating interlayer 22 to fill up the contact hole a conductive plug 23 which is connected electrically to the impurity region 21 and fills up the contact hole is formed by etching back the conductive layer of w until a surface of the insulating interlayer 22 is exposed a barrier layer 30 may be optionally formed on the conductive plug 23 to prevent reaction between the conductive plug 23 material and a storage electrode if a barrier layer 30 is used it is preferably formed with one of tin ti u2014 si u2014 n ti u2014 al u2014 n and the like and is preferably recessed in the contact hole after an amorphous silicon layer doped with impurities has been deposited by cvd on the insulating interlayer 22 including the exposed surface of the conductive plug 23 a storage electrode 24 is patterned by etching the amorphous silicon layer anisotropically by photolithography the storage electrode 24 may be formed in any suitable shape including a box cylinder fin and the like however a box type storage electrode is preferred due to design rules referring to fig5 the surface area of the storage electrode 24 is increased by making the surface irregular preferably by selectively forming a plurality of hemispherical protruding parts 25 by carrying out a hsg formation step on the exposed surface of the storage electrode 24 as a result a final storage electrode 24 and 25 is attained by the storage.