Abstract: To prevent the extraction of electrons from the floating gate during a read operation. A semiconductor memory device comprises a selection gate 3a provided in a first region on a substrate 1 through an insulating film 2, a floating gate 6a provided in a second region adjacent to the first region through an insulating film 5, a first and second diffusion regions 7a and 7b provided in a third region adjacent to the second region, and a control gate 11 provided over the floating gate 6a through an insulating film 8, the control gate 11 intersects with the selection gate 3a at different levels, a third diffusion region 21 is provided in a fourth region located near an extending part of the selection gate 3a on the surface of the substrate, the floating gate 6a is formed in the form of a side wall, and it has a round part 6b at the top on the side directed to the side wall surface of the selection gate 3a.

Abstract: To prevent the extraction of electrons from the floating gate during a read operation. A semiconductor memory device comprises a selection gate 3a provided in a first region on a substrate 1 through an insulating film 2, a floating gate 6a provided in a second region adjacent to the first region through an insulating film 5, a first and second diffusion regions 7a and 7b provided in a third region adjacent to the second region, and a control gate 11 provided over the floating gate 6a through an insulating film 8, the control gate 11 intersects with the selection gate 3a at different levels, a third diffusion region 21 is provided in a fourth region located near an extending part of the selection gate 3a on the surface of the substrate, the floating gate 6a is formed in the form of a side wall, and it has a round part 6b at the top on the side directed to the side wall surface of the selection gate 3a.