METHOD FOR FABRICATING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for fabricating a flash memory device is provided to reduce the number of fabrication processes by forming an isolated floating gate using a mask pattern and forming a control gate using a damascene method. CONSTITUTION: A mask layer is patterned on a semiconductor substrate(10). A trench is formed by etching an exposed part of the semiconductor substrate(10). The trench is buried by forming an oxide layer. The oxide layer is removed by performing a planarization process. The remaining oxide layer is etched. A tunnel oxide layer(14) and a floating gate are formed on the semiconductor substrate between the remaining oxide patterns. The remaining oxide patterns are removed from the semiconductor substrate. A source/drain(16) is formed by performing an ion implantation process. An etch stop layer is formed on the entire surface of the semiconductor substrate. An insulating layer is formed thereon. A part of the floating gate is exposed by patterning the insulating layer and the etch stop layer. A dielectric layer(19), a polysilicon layer(20), and a metal layer(21) are formed on the entire surface of the semiconductor substrate. A control gate is formed by removing partially the metal layer(21).