METHOD OF MANUFACTURING FLASH MEMORY CELL

摘要

PURPOSE: A method of manufacturing a flash memory cell is provided to prevent increase of leakage current due to concentration of electric field by minimizing grain boundary density. CONSTITUTION: A tunnel oxide layer(102) and the first silicon layer(103) are sequentially formed on a semiconductor substrate(100). SPG(Solid Phase Growth) annealing is performed in the first silicon layer to minimize grain boundary density over the tunnel oxide layer. After forming a pad nitride layer on the first silicon layer, an isolation region of the substrate is opened through etching process. Then a trench is formed in the isolation region. After rounding the upper and bottom side of the trench by annealing, the trench is filled with insulation material to form an isolation layer(108). The pad nitride layer is then removed and the second silicon layer(109) is formed over the first silicon layer(103) such that the periphery of the second silicon layer is overlapped with the isolation layer(108). After forming a dielectric layer(113), a control gate silicon layer(114) and a silicide layer(115), an etching process by using control gate mask and self-alignment is performed on the substrate.