Nonvolatile semiconductor memory device and method of fabricating the same

摘要

A nonvolatile semiconductor memory device having a gate insulating film with a memory function. An impurity layer having the same conductivity type as that of the substrate region is formed in that substrate region, underlying the gate insulating film having a memory function, in which a channel is formed. The impurity layer has an impurity profile in which a peak of an impurity concentration is in the region distanced by 500 ANGSTROM or less from the surface of the substrate region and the impurity concentration is 1x1018 cm-3 or less in the region at the depth of 500 ANGSTROM or more.