METHOD FOR MANUFACTURING OF FIELD AREA IN SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing of field area in semiconductor memory device is provided to improve reliability in a process of etching a floating gate and a contact, by making the thickness of an ununiform isolation region generated by a chemical mechanical polishing(CMP) process while using a wet etch process. CONSTITUTION: A tunnel insulation layer(32), a conductive layer and the first insulation layer which have different thicknesses are sequentially formed on a semiconductor substrate(31). An isolation region of a predetermined depth is formed in a predetermined region of the semiconductor substrate. The second insulation layer(37) and the third insulation layer are sequentially formed on the entire surface. The third insulation layer is planarized by a CMP process. The second and third insulation layers are removed by an etch process.