| 摘要 |
A method for fabricating a flash memory device is provided to prevent the lateral surface and the upper part of a conductive layer for a floating gate from being damaged by removing a nitride layer functioning as an etch mask for forming a trench and by performing an isolation layer etching process for adjusting an EFH(effective field oxide height) in a condition that only an isolation layer is dry-etched and a conductive layer is not etched. A floating gate pattern in which a tunnel oxide layer(102), a first conductive layer(103) and a nitride layer are stacked is formed in a first region of a semiconductor substrate(101), and an isolation layer(106) is formed in a second region of the semiconductor substrate. The isolation layer is removed by the thickness of the nitride layer. After the nitride layer is removed, a predetermined thickness of the isolation layer is etched by a dry etch process in a condition that the first conductive layer is not etched and only the isolation layer is etched. A dielectric layer, a second conductive layer and a hard mask layer are formed on the resultant structure and are patterned to form a control gate. The floating gate pattern is etched by using the control gate as a mask to form a floating gate.
|
