Flash memory device and method for fabricating the same

A method of fabricating a flash memory device comprising the steps of:

• forming a first trench having a width including an active region and an isolation region at each side thereof on a predetermined position of a semiconductor substrate;
• filling up a sacrificial layer in the first trench;
• patterning the sacrificial layer to expose the isolation regions of the first trench;
• forming a source region and a drain region by implanting a predetermined conductive type impurity ions into the exposed first trench regions;
• forming an isolation layer by filling up an insulating layer in the exposed first trench regions;
• removing the patterned sacrificial layer to form a second trench exposing the active region;
• forming a tunnel oxide layer and a floating gate sequentially on a surface of the second trench;
• forming a control gate with a gate insulating layer interposed on the floating gate and the substrate;
• and
• forming metal wirings to be in contact with the source and the drain regions, respectively, through the isolation layer on the substrate.