Nonvolatile semiconductor memory device and method of forming same

Abstract

A nonvolatile semiconductor memory device according to an embodiment comprises: a memory cell array including a plurality of memory layers; and a control unit configured to control a voltage applied to the memory cell array. Each of the memory layers comprises a first line and a second line, and further includes a memory cell disposed between the first line and the second line and including a variable resistance element. The control unit is configured to, when executing a forming operation on the memory cell array, execute the forming operation sequentially on the plurality of memory layers. The forming operation is executed sequentially on the memory layers in ascending order of a magnitude of a non-selected current flowing in a non-selected memory cell during the forming operation.