NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

PROBLEM TO BE SOLVED: To solve the following problem: there is a limit of higher capacity of a ROM since a minimum size of a transistor is determined depending upon limits of manufacturing technologies. SOLUTION: The nonvolatile semiconductor memory device has an EEPROM configured to store data based on whether or not electric charge is accumulated in a charge storage film of a memory transistor, and a mask ROM configured to store data based on whether or not a select contact hole is present, the EEPROM and mask ROM, both being united together on the same plane. Consequently, the ROM capacity can be increased without making the transistor size small. COPYRIGHT: (C)2011,JPO&INPIT