Nonvolatile semiconductor memory device

Abstract

A nonvolatile semiconductor memory device with high repair efficiency prevents over-erasing even if a memory cell is replaced in the word line direction. The nonvolatile semiconductor memory device includes the following: erasing bias circuits for erasing data in normal memory cell arrays and a redundancy memory cell array; erasing decode circuits for decoding defective address information; and redundancy control circuits connected in series so that a preceding stage controls the next in order to store defective address information based on an erasing decode signal and to switch the erasing bias circuits based on the defective address information. In erasing data, the redundancy control circuits switch the erasing bias circuits so as to inhibit the application of an erasing bias to word and source lines connected to control gates of the normal memory cell array that is replaced by the redundant memory cell array and also inhibit the erasing bias application to those connected to control gates of the unused redundant memory cell array.