Abstract: A non-volatile semiconductor storage device includes a control circuit performing an erase operation to erase data from a selected one of memory transistors. The control circuit applies a first voltage to the other end of selected one of selection transistors, causes the selected one of the selection transistors to turn on, and causes any one of the memory transistors to turn on that is closer to the selection transistor than the selected one of the memory transistors. The control circuit also applies a second voltage lower than the first voltage to a gate of the selected one of the memory transistors. Such a potential difference between the first voltage and the second voltage causing a change in electric charges in the electric charge storage layer.

Abstract: A nonvolatile semiconductor memory according to examples of the present invention comprises a memory cell and a peripheral transistor. The memory cell has a first intergate insulating film having a multilayer structure and provided on a floating gate electrode and an isolation insulating layer. The peripheral transistor has a second intergate insulating film having a multilayer structure and provided on a first gate electrode and a second isolation insulating layer. The first and second intergate insulating films have the same structure, and a lowermost insulating layer of the first intergate insulating film on the first isolation insulating layer is thinner than a lowermost insulating layer of the second intergate insulating film on the second isolation insulating layer.

Abstract: In a semiconductor device, the side walls are made of SiO2, SiN or SiON, and the top insulating film or gate insulating film is made of an oxide including Al, Si, and metal element M so that the number ratio Si/M is set to no less than a number ratio Si/M at a solid solubility limit of SiO2 composition in a composite oxide including metal element M and Al and set to no more than a number ratio Si/M at the condition that the dielectric constant is equal to the dielectric constant of Al2O3 and so that the number ratio Al/M is set to no less than a number ratio Al/M where the crystallization of an oxide of said metal element M is suppressed due to the Al element and set to no more than a number ratio Al/M where the crystallization of the Al2O3 is suppressed due to the metal element M.