REGISTER FORMING METHOD OF FLASH MEMORY ELEMENT

PROBLEM TO BE SOLVED: To provide a register forming method of a flash memory element for forming a register by the flash memory element applying SAFG process. SOLUTION: The register forming method of the flash memory element comprises the steps of: etching a predetermined region of an element isolation film 102 to form a trench after forming the element isolation film 102 in a semiconductor substrate as shown in Fig. 3b; carrying out a polishing until an upper portion of the element isolation film 102 is exposed after forming a first polysilicon film 104 at an upper portion of the whole structure; forming a second polysilicon film 108 after forming a dielectric film pattern; etching a predetermined region of the second polysilicon film to separate a portion where the first polysilicon film 104 and the second polysilicon film are linked from the second polysilicon film formed at an upper part of the dielectric film pattern; and forming an interlayer insulating film at the upper portion of the whole structure to form a contact plug in a predetermined region of the interlayer insulating film and the second polysilicon film. COPYRIGHT: (C)2007,JPO&INPIT