METHOD FOR FORMING FLASH MEMORY DEVICE

摘要

A method of forming a flash memory device is provided to improve an alignment margin by forming a floating electrode on a cell array region by a self-aligning method. A trench defining an active region is formed on a field region of a semiconductor substrate(10) having a top side of a first height. An oxide layer(20a) is formed thereon. The oxide layer includes an isolation part(20b) for filling the trench and an isolation part(20c) having a top side of a second height. An isolation layer for defining a floating electrode region is formed by reducing a width of the isolation part in comparison with a width of the trench. A floating electrode(40a) self-aligned by the isolation layer is formed on the active region of the semiconductor substrate.