NONVOLATILE MEMORY AND SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a multi-valued nonvolatile memory which can effectively control short channel effect. SOLUTION: Impurity regions (pinning regions) in stripes in the direction of the length are formed in an active region which a memory transistor has. The pinning region in a drain region keeps a depletion layer from extending, and controls short channel effect accompanying miniaturization. The memory transistor assigns one value or one bit data to each channel forming region, to obtain multi-valued operation. More specifically, the memory transistor has floating gate electrodes formed on a plurality of channel forming regions through a first gate insulation film, and can apply potentials independently to a plurality of the pining regions respectively.