| 摘要 |
An electrically-erasable non-volatile semiconductor memory element comprises a floating gate (FG) separated from a semiconductor substrate by a first insulating film (OX1), and an erase-only or write/erase gate (EG) formed on a second insulating film (OT3) on the floating gate. The second insulating film is an oxidized film formed by thermal oxidation of polycrystalline silicon to have a thickness in the range from 1.5x10<-><8> to 4x10<-><8> metre. With such a second insulating film the amount of electrons trapped in the second insulating film is decreased, thereby increasing the number of write/erase cycles that the element can usefully withstand. |
