A flash memory device and a method of manufacturing a flash memory device. A flash memory device may include an isolation layer and/or an active area over a semiconductor substrate, a memory gate formed over an active area, a control gate formed over a semiconductor substrate including a memory gate, and/or a common source line contact formed over a semiconductor substrate including a control gate. A flash memory device may include a source plate having substantially the same interval as an interval of an active area of a bit line. A source plate may include an active area in which a common source line contact may be formed. A common source line contact may include a long butting contact extending in a direction traversing an active area.