METHOD FOR MANUFACTURING FLASH MEMORY

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flash memory which can form cell regions and peripheral circuit regions by differentiating their trench depths at a shallow trench isolation process time of the memory. SOLUTION: The method for manufacturing the flash memory includes a step of sequentially vapor depositing a pad oxide film and a pad nitride film on a semiconductor substrate; a step of forming the trenches, having different depths in the cell region and the peripheral circuit region by regulating the etching angle and etching target by the width of the trench; a step of forming the trench of the peripheral circuit region further deeper than the trench of the cell region; a step of vapor depositing a trench-insulating film on the upper part surface of the overall structure and embedding the film in the trench; a step of forming the trench insulating film having a projecting shape in the upper part structure by performing a flattening step and a stripping step of the trench-insulating film; a step of forming a well region by an ion implanting step; and a step of forming a tunnel oxide film, a floating gate, a dielectric film and a control gate. COPYRIGHT: (C)2004,JPO