A semiconductor device is provided. The device includes a plurality of transistor pairs that are stacked over a substrate. Each of the plurality of transistor pairs includes a n-type transistor and a p-type transistor that are stacked over one another. The device also includes a plurality of gate electrodes that are stacked over the substrate with a staircase configuration. The plurality of gate electrodes are electrically coupled to gate structures of the plurality of transistor pairs. The device further includes a plurality of source/drain (S/D) local interconnects that are stacked over the substrate with a staircase configuration. The plurality of S/D local interconnects are electrically coupled to source regions and drain regions of the plurality of transistor pairs.