SEMICONDUCTOR MEMORY DEVICE AND SEMICONDUCTOR MEMORY ELEMENT

摘要

A semiconductor memory element for writing by a drain-avalanche hot electron includes a MOS transistor having a first semiconductor layer of a second conductivity type formed on a semiconductor substrate of a first conductivity type; a floating gate provided on the first semiconductor layer through intermediation of an insulating film; a channel region formed in a surface of the first semiconductor layer under the floating gate; and a source region and a drain region of the first conductivity type provided on the first semiconductor layer so as to be in contact with the channel region in which the channel region has a distribution of at least two kinds of carrier densities.