NONVOLATILE SEMICONDUCTOR MEMORY, ITS OPERATING METHOD AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To obtain a nonvolatile semiconductor memory in which the occupation area of a nonvolatile semiconductor memory element is reduced extremely, deterioration in the characteristics of the element due to punch through or the like can be prevented readily, and a source side injecting operation can be effected. SOLUTION: The nonvolatile semiconductor memory comprises a first conductivity type semiconductor region SUB having a level difference on the surface, two second conductivity type semiconductor regions S/D isolated in the direction perpendicular to the major surface of the first conductivity type semiconductor, a memory gate electrode WL1 facing a part of the side face of the level difference through a first gate dielectric film GD1 including a spatially dispersed charge storage means, and control gate electrodes CL1-CL4 facing a part of the side face of the level difference through a second gate dielectric film GD having no charge storing power. The control gate electrode may comprise a conductive sidewall SW, as shown on the drawing, or the memory gate electrode may comprise the conductive sidewall SW.