Patent ID: 6340611
Filing Date: 2002-01-22
Classification: H01L

Abstract:
A method for manufacturing a nonvolatile semiconductor memory device comprising the steps of:forming a first conductive layer on a semiconductor substrate with a first insulating layer interposed therebetween; forming a first mask layer having a predetermined first pattern on said first conductive layer; forming a plurality of trenches in said substrate through said first conductive layer and said first insulating layer by etching with use of said first mask layer as a mask; forming a second insulating layer in said plurality of trenches such that said insulating layer is formed up to an upper surface of said first mask layer; exposing said first conductive layer by etching said first mask layer; forming a second conductive layer on an upper surface of said first conductive layer and on an upper surface of said second insulating layer; removing parts of said second conductive layer located on said second insulating layer to expose parts of said upper surface of said second insulating layer; forming a third insulating film on said second conductive layer and said second insulating layer exposed; and forming a third conductive layer on said third insulating layer.