15 through the etching process employing the polysilicon layer 17 of the hemisphere grain structures as a mask and removing the remaining polysilicon layer 17 of the hemisphere grain structures as shown in fig1 e since the oxide layer 15 on which the polysilicon layer 17 of the hemisphere grain structures is not formed is exposed the exposed oxide layer is etched through the etching process however the oxide layer 15 on which the polysilicon layer 17 of the hemisphere grain structures is formed is not etched because the polysilicon layer 17 of the hemisphere grain structures prevents the oxide layer 15 from being etched through the etching process in case the etch ratio of the polysilicon layer to the oxide layer is more than 20 1 therefore several cylinder shaped oxide patterns 19 are formed fig1 f is a cross sectional view illustrating the formation of storage electrodes after depositing a second polysilicon layer used for the storage electrode as shown in fig1 f a second polysilicon 21 is deposited on the cylinder shaped oxide patterns and exposed surface of the first polysilicon layer and the first polysilicon layer 11 and second polysilicon layer 21 are etched by the etching process using a mask for forming the storage electrodes so that the storage electrodes 30 having the first polysilicon layer.