In a method of fabricating a
flash memory device, after an isolation trench is formed, a bottom surface and sidewalls of the trench are gap-filled with a HARP film having a favorable step coverage. A wet etch process is performed such that the HARP film remains on the sidewalls of a tunnel
dielectric layer, thereby forming a wing spacer. Accordingly, the tunnel
dielectric layer can be protected and an
interference phenomenon can be reduced because a control gate to be formed subsequently is located between floating gates.