Semiconductor devices and methods of fabricating the same

摘要

One example embodiment of a semiconductor device includes a memory cell array formed on a substrate. The memory cell array includes a gate stack including alternating conductive and insulating layers. A first lower conductive layer in the gate stack has a portion disposed below a first upper conductive layer in the gate stack, and a first contact area of the first lower conductive layer is disposed higher than a second contact area of the first upper conductive layer. The semiconductor device further includes first and second contact plugs extending into the gate stack to contact the first and second contact areas, respectively.