Nonvolatile semiconductor memory device

Abstract

A nonvolatile semiconductor memory device includes a substrate including device regions extending in a first direction, a memory cell array region including a plurality of memory cells disposed on the device regions, bit lines extending in the first direction, a sense amplifier circuit connected to ends of the bit lines, and bit line contacts connecting device regions to bit lines. The memory cell array region includes first to N-th regions where N is an integer of two or more, and a K-th region is located at a greater distance from the sense amplifier circuit than a (K−1)-th region, where K is an arbitrary integer of 2 to N. Contact resistance of the bit line contacts in the K-th region is lower than contact resistance of the bit line contacts in the (K−1)-th region, each device region having constant width in the memory cell array region.