Semiconductor memory device

Abstract

A semiconductor memory device comprising a substrate including a cell region, first and second contact regions, and a bit peripheral circuit region disposed between the first and second contact regions. A first stack structure is disposed on the cell region and the first contact region. A second stack structure is disposed on the cell region and the second contact region. A peripheral transistor is disposed on the bit peripheral circuit region and is electrically connected to the first and second stack structures. Each of the first and second stack structures comprises semiconductor patterns vertically stacked on the cell region, and conductive lines having connection with the semiconductor patterns and extending along a first direction from the cell region onto corresponding first and second contact regions. The conductive lines have stepwise structures on the first and second contact regions.