| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of fabricating a flash memory element capable of improving a difference in an EFH caused by the protrusions of an element isolation layer in each of a high voltage transistor region and a low voltage transistor/cell region, between these regions to ensure the stability of processes thereby promoting the reliability of the element. SOLUTION: The method of fabricating a flash memory element includes steps of providing a semiconductor substrate 21 that has a high voltage transistor region HV defined, in the region of a first element isolation layer and a low voltage transistor/cell region LV/CELL defined in the region of a second element isolation layer; forming a planarizing layer on a first polysilicon layer 23; removing the planarizing layer and the top end portion of the element isolation layer 260 in the low voltage transistor/cell region by a predetermined thickness by a first etching process; removing the planarizing layer and the top end portion of the element isolation layer in the high voltage transistor region and the low voltage transistor/cell region by a second etching process; and forming a second polysilicon layer 29 on the first polysilicon layer including the element isolation layer. COPYRIGHT: (C)2005,JPO&NCIPI
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