METHOD OF FABRICATING A SEMICONDUCTOR DEVICE

摘要

A method of fabricating a semiconductor device is provided to improve the reliability of the device by removing residue when a conductive layer used as a floating gate material is planarized. After a tunnel insulating layer(120a) and a conductive layer are deposited on a semiconductor substrate(110a) and the conductive layer is patterned, an isolation region is formed by using the conductive layer. A first insulating layer(140b) is deposited in the isolation region, and then is subjected to a first planarization process by using the conductive layer as a first stop layer to expose the conductive layer. The exposed conductive layer(130b) is recessed. A buffer layer(150a) is deposited, and then is subjected to a second planarization process by using the first insulating layer as a second stop layer. The first insulating layer is recessed, and then a second insulating layer(160) is deposited. The substrate is subjected to a third planarization process by using the buffer layer, and then the buffer layer is removed.