METHOD FOR SALICIDING SOURCE LINE IN FLASH MEMORY HAVING STI

PROBLEM TO BE SOLVED: To provide a salicide source line in a flash memory having a shallow trench isolation(STI) structure by forming a side wall of an insulator on a side surface where the source is exposed and forming a silicide layer in a region positioned lower than the insulated structure on a semiconductor substrate. SOLUTION: A nitride thin film 110 of 50-600 thick is formed on a structure. Then, the nitride oxide thin film 110 is etched to expose a region for an oxide trench 160. Next, a structure 70 for shallow trench isolation is formed by etching. Following the formation of an oxide side wall 130 and an oxide trench 160, blanket implantation of dopant species is performed to form a source line structure 24, and a patterned resist layer 120 is removed. Subsequently, any of metals reacts with a silicon region thereunder to form a silicide region. Any part of the metal that has not reacted is etched off to form a source-line silicided region 140.