Patent attributes
A control gate includes a first conductive film formed in contact with an inter-gate insulating film and a second conductive film electrically connected to the first conductive film. An inter-level insulating film which insulates first and second stacked gate structures from each other. The inter-level insulating film includes a first insulating film, a second insulating film, and a third insulating film formed between the first and second insulating films. The first insulating film insulates the floating gates from each other and portions of the control gates from each other. The second and third insulating films insulate the other portions of the control gates from each other. The third insulating film has a selective etching ratio with respect to the first and second insulating films.
