METHOD FOR FABRICATING SEMICONDUCTOR DEVICE TO IMPROVE CHARACTERISTIC OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to improve the characteristic of a semiconductor device by patterning a precise size of a lowermost polysilicon layer while using an uppermost oxide layer as an etch barrier such that the uppermost oxide layer is patterned along a photoresist layer pattern in a structure including the polysilicon layer and the oxide layer. CONSTITUTION: The first polysilicon layer(20) for a floating gate, an ONO insulation layer(30), the second polysilicon layer(40) for a control gate and an oxide layer(50) are sequentially stacked. A photoresist layer pattern is formed on the oxide layer. The oxide layer is selectively etched. The photoresist layer pattern is eliminated. The second polysilicon layer, the ONO insulation layer and the first polysilicon layer are sequentially and selectively etched by using the oxide layer as a mask. A nitride layer is formed and patterned on the resultant structure. The third polysilicon layer for a select gate is formed on the resultant structure.