FLASH MEMORY DEVICE HAVING SELF-ALIGNED SHALLOW TRENCH ISOLATION AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A flash memory device having a self-aligned STI(Shallow Trench Isolation) and a manufacturing method thereof are provided to be capable of preventing a bird's beak from being formed at the edge portion of a tunnel oxide pattern. CONSTITUTION: A flash memory device is provided with a semiconductor substrate(100), a tunnel oxide pattern formed at the predetermined upper portion of the substrate, and a floating gate pattern(150) formed at the upper portion of the tunnel oxide layer. The floating gate pattern includes a trench region(112a) adjacent to the tunnel oxide pattern. The flash memory device further includes a trench oxide layer(118) and an isolating pattern(120) formed at the upper portion of the trench oxide layer. At this time, a nitrogen doping layer is formed at each surface of the sequentially aligned sidewalls for the floating gate pattern and the trench region.