Method of manufacturing flash memory device

摘要

Disclosed is a method of manufacturing a flash memory device. In a flash memory device using a SA-STI scheme, a trench for isolation is buried with oxide. A field oxide film is then formed by means of a polishing process. Next, field oxide films of a cell region and a low-voltage transistor region are selectively etched by a given thickness. As EFH values of the cell region, the low-voltage transistor region and the high-voltage transistor region become same or similar, it is possible to secure stability of a subsequent process.