US Patent 9741439 Non-volatile semiconductor memory device

According to one embodiment, a non-volatile semiconductor memory device comprises a memory cell array and a memory region. The memory cell array has a plurality of physical blocks. Each of the plurality of physical blocks includes a plurality of string units. Each string unit has a plurality of NAND strings that shares a plurality of word lines connected to a plurality of memory cells, respectively. The memory region is disposed to one of the plurality of physical blocks. Each of the plurality of string units configures a first logical block, and when the first logical block is failed, information of the first failed logical block is stored in a first region of the memory region.