US Patent 9318159 Semiconductor device

Disclosed herein is a semiconductor device including a multi-level wiring structure that includes a lower-level wiring, an upper-level wiring and an interlayer insulating film between the lower-level and upper-level wirings. The device further includes a plurality of bit lines for a plurality of memory cells, and each of the bit lines includes a first portion that is formed as the lower-level wiring and a second portion that is electrically connected in series to the first portion and formed as the upper-level wiring.