METHOD FOR MANUFACTURING STORAGE ELECTRODE OF MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a storage electrode of a memory device is provided to guarantee sufficient capacitance and insulating stability between adjacent storage electrodes, by forming a polysilicon layer for forming the storage electrode while using two layers having different impurity density. CONSTITUTION: The first auxiliary layer for forming a capacitor is stacked after a buried contact(17) is formed. The first auxiliary layer is patterned to form an empty space over the buried contact. The first polysilicon layer(25) doped with high-density impurities is stacked. The second polysilicon layer(27) doped with low-density impurities is stacked. The second auxiliary layer is stacked to fill a remaining space after the first and second polysilicon layers are filled in the empty space. The first and second polysilicon layers stacked on the first auxiliary layer are eliminated by a surface planarization process. The first and second auxiliary layers are etched away. A hemispherical grain(HSG)(31) is formed on the first and second polysilicon layers left and exposed.