METHOD FOR FORMING CHARGE STORAGE NODE OF SEMICONDUCTOR DEVICE TO COMPLETELY REMOVE REMNANTS OF BURIED OXIDE LAYER CAPABLE OF BEING FORMED BETWEEN GRAINS OF MPS LAYER AND SUFFICIENTLY OVERCOME PARTICLE PROBLEM

摘要

PURPOSE: A method for forming a charge storage node of a semiconductor device is provided to completely remove remnants of a buried oxide layer capable of being formed between grains of an MPS(meta-stable polysilicon) layer and sufficiently overcome a particle problem by adding H2 to F-based main etch gas in a blanket etch process for exposing a polysilicon layer in which the MPS layer covered with the buried oxide layer is formed. CONSTITUTION: A conductive layer and a hemispherical polysilicon layer for a charge storage node are formed along the surface of a substrate(21) with a step by a predetermined process. A planarized oxide layer is formed on the hemispherical polysilicon layer. By a dry etch process using fluorine-based gas, the oxide layer is blanket-etched to expose the hemispherical polysilicon layer. A dry etch process using fluorine-based to which hydrogen gas is added is performed on the hemispherical polysilicon layer to eliminate the oxide layer remaining between the grains of the hemispherical polysilicon layer.