Patent ID: 7224019

Claim:
A semiconductor device comprising: a semiconductor substrate including a main surface; an electrically rewritable semiconductor memory cell provided on the semiconductor substrate, the memory cell comprising an island semiconductor portion provided on the main surface of the semiconductor substrate or above the semiconductor substrate, a first insulating film provided on a top surface of the island semiconductor portion, a second insulating film provided on a side surface of the island semiconductor portion and being smaller in thickness than the first insulating film, and a charge storage layer provided on the side surface of the island semiconductor portion with the second insulating film interposed therebetween and on a side surface of the first insulating film, wherein the island semiconductor portion comprises a first side surface and a second side surface opposed to the first side surface, and the charge storage layer comprises a first sidewall provided on the first side surface of the island semiconductor portion and a second sidewall provided on the second side surface of the island semiconductor portion; a third insulating film provided on the charge storage layer; and a control gate electrode provided on the third insulating film.