Patent ID: 7537992

Claim:
A method of manufacturing a flash memory device, comprising: preparing a semiconductor substrate having an active region and a field region; forming a device insulating layer in the field region; forming a tunneling oxide layer on the active region; forming a first polysilicon layer on the tunneling oxide layer; coating a photoresist on the first polysilicon layer and selectively patterning the coated photoresist to define a floating gate region, wherein the patterned photoresist is only on the active region; etching by a predetermined thickness a portion of the first polysilicon layer overlapping the device insulating layer using the patterned photoresist as a mask; forming a polymer on sides of the patterned photoresist; forming a floating gate by selectively removing the polysilicon layer using the photoresist and the polymer as a mask; and removing the photoresist and the polymer.